Compositions and methods for treating inflammation and auto-immune diseases

ABSTRACT

Compositions containing soluble B7-H4 (sH4) antagonists in an amount effective to reduce, inhibit, or mitigate an inflammatory response in an individual and methods for the treatment or prophylaxis of inflammatory disorders and autoimmune diseases or disorders are provided. Soluble H4 has been discovered to interfere with B7-H4 activity including B7-H4&#39;s activity as an inhibitor of T cell immunity. Thus, interference of sH4 biological activity is an effective method to restore B7-H4 activity and thereby provide an effective method for treating inflammatory diseases or disorders including autoimmune diseases or disorders.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit of and priority to U.S. Ser. No.60/877,319 filed on Dec. 27, 2006 and U.S. Ser. No. 60/949,742 filed onJul. 13, 2007, both of which are incorporated by reference in theirentirety.

GOVERNMENT SUPPORT

This invention was made with Government support under Grant No. R01CA98731, awarded by the National Institutes of Health. The Governmenthas certain rights in this invention.

TECHNICAL FIELD

In general, this invention relates to compositions and methods formodulating inflammatory responses, in particular to compositions andmethods for treating or inhibiting inflammatory responses related toautoimmune disorders.

BACKGROUND OF THE INVENTION

Modulating immune responses is important in the treatment of manydiseases and disorders. For example, it would be advantageous to enhancean immune response in patients suffering from cancer or infection.Alternatively, it would be beneficial to inhibit or reduce an immuneresponse in patients suffering from inflammatory conditions.

Chronic and persistent inflammation is a major cause for thepathogenesis and progression of systemic autoimmune diseases such asrheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). RA isa highly inflammatory polyarthritis often leading to joint destruction,deformity and loss of function. Additive, symmetric swelling ofperipheral joints is the hallmark of the disease. Extra-articularfeatures and systemic symptoms can commonly occur and may antedate theonset of joint symptoms. Chronic pain, disability and excess mortalityare unfortunate sequelae. During progression of RA, the synovial lininglayer of the inflamed joints increases its thickness as a result ofsynovial hyperplasia and infiltration into synovial stroma by CD4+ Tcells, B cells, CD8+ T cells, macrophages, dendritic cells andneutrophils (Feldmann, M. et al., Cell, 85:307-10 (1996); Moreland, L.W. et al., N Engl J Med, 337:141-7 (1997)). In SLE, the production ofautoantibodies results in the deposition of immune complex in manytissues and organs including glomeruli, skin, lungs and synovium,thereby generating rheumatic lesions with characteristic chronicinflammation and tissue damage.

In several arthritis models, depletion of neutrophils resulted in adecrease of arthritis severity. The most common animal model for RA iscollagen-induced arthritis (CIA) in which challenge with type II chickencollagen (CII) induces persistent chronic inflammation in all majorjoints of DBA/1 j mice (Williams, R. O., et al., Proc Natl Acad Sci USA,91:2762-6 (1994)). While CD4+ T cells have long been considered to playa central role in the pathogenesis of RA, there is renewed interest inaddressing the pivotal role of neutrophils in initiation, progressionand maintenance of RA. Massive infiltration of neutrophils in thelesions releases the proinflammatory cytokines including TNF-α, IL-1 andIL-6, which can affect the functions of neutrophils and otherinflammatory cells.

An extensively studied murine model for SLE is the lpr strain, in whichmutation of Fas apoptotic gene leads to spontaneous autoimmune disorderssimilar to human SLE. Studies in this strain recapitulate many aspectsof human SLE symptoms. For example, lpr mice develop anti-chromatin,anti-DNA, and anti-IgG serum autoantibodies as well as a polyclonalincrease of total immunoglobulin. Disease severity is highly dependenton genetic background. For example, MRL-lpr/lpr mice produce high levelsof IgG autoantibodies to DNA and develop a severe glomerulonephritis dueto deposition of immune complexes, while C57BL/6(B6)-lpr/lpr miceproduce low level autoantibodies with much mild immunopathology.

Co-signal molecules, including those with costimulatory and coinhibitoryfunctions, are important for the induction of effective immune responseand for the prevention of unwanted autoimmunity. It has been shown thatsignals through the B7-CD28 family are major regulators of this balanceand play a pivotal role in the regulation of autoimmunity. Persistenceof inflammatory responses in systemic autoimmune diseases implies eitheran impaired coinhibitory or enhanced costimulatory functions, leading tothe loss of the balance. In this regard, it is particularly interestingthat autoantibodies against B7-H1, a primary coinhibitory molecule afterbinding to its receptor PD-1, is found in a significant proportion of RApatients and the presence of the autoantibodies is implicated in theprogression of RA symptoms.

Soluble forms of B7-CD28 family molecules are also implicated in theprogression of rheumatoid diseases. A recent study shows that solublePD-1 could be detected in RA patients and the levels of soluble PD-1 arecorrelated with TNF-alpha concentration in synovial fluid. B7-H4 is amore recent addition to the B7 family member. B7-H4 has potentinhibitory effects on T cells through binding to a putative receptor.Cell surface B7-H4 is normally not detectable in normal tissues,although its surface expression could be upregulated on macrophages andtumor cells by inflammatory cytokines, including IL-10 and IL-6. It hasbeen reported that B7-H4 could suppress T cell response in the presenceof antigen stimulation. Soluble B7-H4 (sH4) has also been detected inovarian cancer patients as a potential biomarker, but the mechanism ofproduction and the function of sH4 is unknown. B7-H4 deficient mice werefound to mount slightly enhanced T helper 1 type T cell responsesagainst Leishmania major infection. Using independently generated B7-H4knockout mice, it was demonstrated that the lack of B7-H4 led toresistance to Listeria monocytogenes infection occurs by directregulation of growth of neutrophil progenitors. In summary, althoughB7-H4 clearly plays a role in immunity, especially autoimmunity andresistance to infection, the mechanism is not clear.

Therefore, it is object of the invention to provide compositions andmethods for the treatment of autoimmune disorders.

It is another object to the invention to provide compositions andmethods for the treatment of inflammatory responses.

It is still another object to provide methods and compositions forinhibiting, reducing, or blocking the biological activity of solubleB7-H4.

SUMMARY OF THE INVENTION

Compositions containing soluble B7-H4 (sH4) antagonists in an amounteffective to reduce, inhibit, or mitigate an inflammatory response in anindividual and methods for the treatment or prophylaxis of inflammatorydisorders and autoimmune diseases or disorders have been developed. Ithas been discovered that soluble H4 (“sH4”) interferes with B7-H4activity, including B7-H4 inhibition of T cell immunity. Thus,interference of sH4 biological activity is believed to be an effectivemethod to restore 87-H4 activity and thereby provide an effective methodfor treating inflammatory diseases or disorders, including autoimmunediseases or disorders.

Suitable sH4 antagonists include, but are not limited to, sH4 bindingagents such as antibodies and natural ligands of sH4, nucleic acidsencoding sH4 antagonists, protease inhibitors, B7-H4 polypeptides, B7-H4fusion proteins, and inhibitory nucleic acids specific for sH4 encodingnucleic acids. Another method of treating inflammatory responses orautoimmune diseases or disorders is by administering to an individual inneed thereof an agent that downregulates or inhibits expression of sH4,an agent that inactivates sH4 in viva, an agent that competes for sH4'snatural ligand in vivo, or a combination thereof.

In certain embodiments, neutrophil-mediated inflammation is reduced orinhibited. Representative inflammatory diseases or disorders that can betreated with one or more of the sH4 antagonists to reduce, inhibit ormitigate one or more symptoms include, but are not limited to,autoimmune diseases or disorders including rheumatoid arthritis,systemic lupus erythematosus, alopecia greata, anklosing spondylitis,antiphospholipid syndrome, autoimmune Addison's disease, autoimmunehemolytic anemia, autoimmune hepatitis, autoimmune inner ear disease,autoimmune lymphoproliferative syndrome (ALPS), autoimmunethrombocytopenic purpura (ATP), Behcet's disease, bullous pemphigoid,cardiomyopathy, celiac sprue-dermatitis, chronic fatigue syndrome immunedeficiency syndrome (CFIDS), chronic inflammatory demyelinatingpolyneuropathy, cicatricial pemphigoid, cold agglutinin disease, Crestsyndrome, Crohn's disease, Dego's disease, dermatomyositis,dermatomyositis juvenile, discoid lupus, essential mixedcryoglobulinemia, fibromyalgia—fibromyositis, grave's disease,guillain-barre, hashimoto's thyroiditis, idiopathic pulmonary fibrosis,idiopathic thrombocytopenia purpura (ITP), Iga nephropathy, insulindependent diabetes (Type I), juvenile arthritis, Meniere's disease,mixed connective tissue disease, multiple sclerosis, myasthenia gravis,pemphigus vulgaris, pernicious anemia, polyarteritis nodosa,polychondritis, polyglancular syndromes, polymyalgia rheumatica,polymyositis and dermatomyositis, primary agammaglobulinemia, primarybiliary cirrhosis, psoriasis, Raynaud's phenomenon, Reiter's syndrome,rheumatic fever, sarcoidosis, scleroderma, Sjogren's syndrome, stiff-mansyndrome, Takayasu arteritis, temporal arteritis/giant cell arteritis,ulcerative colitis, uveitis, vasculitis, vitiligo, and Wegener'sgranulomatosis.

Still another method of treating a inflammatory response or autoimmunedisease or disorder is by selectively removing sH4 from the blood orplasma of an individual. The blood or plasma can be treated ex vivo witha binding agent specific for sH4 to selectively remove sH4 from theblood or plasma. The treated blood or plasma can then be returned to theindividual.

The severity of an inflammatory response or autoimmune disease ordisorder can be assessed by determining the level of sH4 in a biologicalsample of an individual and correlating the level of sH4 in the samplewith predetermined amounts of sH4 obtained from individual's atdifferent time points in the progression of the disease or disorder.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing the disruption of the B7-H4 gene.A 4.7 kb DNA fragment containing exons encoding the IgV and IgC domainsof murine B7-H4 gene is substituted by a 1.7 kb fragment encoding theneomycin resistant (Neo) gene. Closed boxes represent B7-H4 codingexons. Lines between exons represent intron sequences. Open boxesrepresent untranslated exons. The Neo is represented by a shaded box.

FIG. 2 a is a line graph of percent survival versus days post Listeriamonocytogenes (LM) infection in wildtype mice (♦) or B7-H4KO mice (□).FIG. 2 b is a graph of CFU/g of spleen (×10⁸) on day 2 or day 3 forwildtype mice (◯) or B7-H4KO mice (▴) infected with LM. FIG. 2 c is aline graph of percent spleen granulocytes versus days post LM infectionin wildtype mice (♦) or B7-H4KO mice (□) infected with LM. FIG. 2 d is abar graph of CFU/g of liver×10⁴ in three B7-H4 KO mice or littermatecontrol i.p. injected with 150 pg Gr-1 mAb or control Rat IgG (LPS-free)24 hours prior to Listeria infection. Mice were then i.p. injected with3×10⁶ CFU of Listeria. Twenty-four hours post infection, mice wereterminated and Listeria in liver was counted.

FIG. 3 is a bar graph of LM CFU/granulocyte versus hours post LMinfection in wildtype mice (♦) or B7-H4KO mice (□).

FIG. 4 is a line graph of percent survival versus days post LM infectionin RKO mice (♦) or B7-H4KO mice (□).

FIG. 5 a is a line graph of CPM versus G-CSF (ng/ml) in two×10⁶ bonemarrow cells of wildtype mice (♦) or B7-H4KO mice (□) plated with theindicated concentration of recombinant G-CSF for 3 days. The cultureswere pulsed with ³HTdR for 18 hrs before the end of culture, harvestedand counted by a scintillation counter. FIG. 5 b is a panel of linegraphs of the dilution of CFSE in gated Gr-1+CD11b+granulocytes analyzedby flow cytometry. Two×10⁶ of bone marrow cell from the indicated micewere labeled with CFSE and cultured for 5 days. Cells were harvested anddoubly stained with Gr-1/CD11b mAb.

FIG. 6 is a line graph of CPM versus days. Two×10⁶ of bone marrow cellsfrom normal B6 mice were plated in the 96-well plates coated with 20μg/ml of recombinant murine B7-H4Ig (□) or murine Ig control protein (▴)in the absence (A) or presence of 0.1 ng/ml (B) or 1 ng/ml (C) ofrecombinant murine G-CSF. Cells were harvested on day 2-5 days asindicated. The cultures were pulsed with ³HTdR for 18 hrs before the endof culture, harvested and counted by a scintillation counter. *P<0.05.

FIG. 7 a is a graph showing sH4 in sera of healthy donors (HA) (♦), RA(▴), and SLE (□) patients. FIG. 7 b is a western blot showing that sH4is present in RA patients and not in healthy donors. FIG. 7 c is a graphshowing the correlation between concentration of the sH4 and theseverity groups 0 (▴), 1 (X), 2 (♦), and 3 (▪) of RA.

FIG. 8 a is a schematic of the B7-H4V, B7-H4VC and B7-H4Ig. IgV domain;IgV, IgC domain; IgC. TM; transmembrane domain, CY; cytoplasmicdomain.FIG. 8 b shows a graph of percent incidence versus days after collageninjection of mice immunized with chicken type II collagen in CFA on day0 and day 21. Three groups of mice were hydrodynamic injection withcontrol vector (□), B7-H4V (▴) or B7-H4VC (▪) on day −1 and day 20;means±s.e.m. (n=5). FIG. 8 c shows a graph of clinical score versus daysafter collagen injection of mice immunized with chicken type II collagenin CFA on day 0 and day 21. Three groups of mice were hydrodynamicallyinjected with control (□), B7-H4V (▴) or B7-H4VC (▪) vector on day −1and day 20; means±s.e.m. (n=5). FIG. 8 d is a bar graph showing serumlevels of anti-CII total IgG. white; control vector, gray; B7-H4V,black; B7-H4VC; means±s.d. FIG. 8 e shows a line graph of counts perminute versus CII μg/ml. Whole splenocytes from CIA mice injected withcontrol vector (□), B7-H4V (▴) or B7-H4VC (▪) on day 30 were cultured inthe presence of the indicated amounts of CII for 72 hr; means±s.d. FIG.8 f shows bar graphs of supernatants of whole splenocytes after a 72 hrculture assessed for IFN-γ and IL-17 production by ELISA; means±s.d.FIG. 8 g shows a line graph of incidence versus days after collageninjection of mice immunized with chicken type II collagen in CFA on day0 and day 21. WT mice (□), B7-H4KO mice (▪); means±s.e.m. (n=5). FIG. 8b shows a line graph of clinical score of mice immunized with chickentype II collagen in CFA on day 0 and day 21. WT mice (□), B7-H4KO mice(▪); means±s.e.m. (n=5).

FIG. 9 a shows a bar graph of an air pouch assay showing sH4 activatesneutrophils by its dominant-negative activity. Subcutaneous air poucheswere injected with LPS (50 μg). After 5 h, Gr-1+ neutrophils werequantified by flow cytometry of cells rinsed from the pouch with sterilesaline. Each bar represents the average of six to eight mice in eachgroup; means±s.d. FIG. 9 b shows a line graph of incidence versus daysafter collagen challenge. Six groups of mice were treated with controlvector and control rat IgG (▴), control vector and anti-Gr-1 Ab (□),B7-H4V and control rat IgG (•) and B7-H4V and anti-Gr-1 Ab (◯), B7-H4VCand control rat IgG (▪) and B7-H4VC and anti-Gr-1 Ab (▪); means±s.e.m.(n=5) FIG. 9 c shows a line graph of clinical score of CIA mice versusdays after collagen challenge. Six groups of mice were treated withcontrol vector and control rat IgG (▴), control vector and anti-Gr-1 Ab(□), B7-H4V and control rat IgG (•) and B7-H4V and anti-Gr-1 Ab (◯),B7-H4VC and control rat IgG (▪) and B7-H4VC and anti-Gr-1 Ab (▪);means±s.e.m. (n=5).

FIG. 10 a shows a line graph of the serum levels of anti-double strandDNA autoantibody in MRL-lpr/lpr mice. Four groups of mice were treatedwith control vector and control rat IgG (▴), control vector andanti-Gr-I Ab (□), B7-H4VC and control rat IgG (▪) and B7-H4VC andanti-Gr-1 Ab (□); means±s.e.m. (n=5). FIG. 10 b shows a line graph ofthe serum levels of anti-double strand DNA autoantibody in B6-lpr/lprmice (□) or B6-lpr/lpr×B7-H4KO mice (▪); means±s.e.m. FIG. 10 c shows apanel of graphs showing weight and total cell number in the spleens andperipheral lymph nodes of 24 weeks old B6-lpr/lpr mice (□) orB6-lpr/lpr×B7-H4KO mice (□). (n=5) FIG. 10 d shows a graph indicatingproteinuria grade of 24 weeks old B6-lpr/lpr mice (□) orB6-lpr/lpr×B7-H4KO mice (□). (n=5).

FIG. 11 a shows a line graph of incidence of mice immunized with chickentype II collagen in CFA on day 0 and day 21. Three groups of mice werehydrodynamic injection with control vector (□) or B7-H4Ig (▪) on day −1and day 20; means±s.e.m. (n=5) FIG. 11 b shows a line graph of clinicalscore of mice immunized with chicken type II collagen in CFA on day 0and day 21. Three groups of mice were hydrodynamic injection withcontrol vector (□) or B7-H4Ig (▪) on day −1 and day 20; means±s.e.m.(n=5) FIG. 11 e shows a bar graph of serum levels of anti-CII total IgG.white; control vector, black; B7-H4Ig; means±s.d. FIG. 11 d shows a linegraph of counts per minute versus CII μg/ml of whole splenocytes fromCIA mice injected with control vector (□) or B7-H4Ig (▪) on day 30 werecultured in the presence or absence of the indicated amounts of CII for72 hr; means±s.d. FIG. 11 e shows bar graphs showing supernatants ofwhole splenocytes after a 72 hr culture assessed for IFN-γ and IL-17production by ELISA; means±s.d.

FIG. 12 shows bar graphs of serum levels of anti-CII IgG1, IgG2a andIgG2b in CIA mice treated with control vector, B7-H4V, B7-H4VC orB7-H4Ig were measured by ELISAs in day 30; means±s.d.

FIG. 13 shows line graphs of counts per minute verses CII μg/mlindicating proliferation of splenic CD4 T cells in CIA mice injectedwith control vector (□), B7-H4V (▴), B7-H4VC (▪) or B7-H4Ig (•) on day30 in the presence of the indicated amounts of CII for 72 hr; means±s.d.

FIG. 14 is a line graph of percent cumulative survival versus age(weeks) in MRL-lpr/lpr mice injected with control mIgG plasmid (□) orB7-H4Ig plasmid (▪) at 6, 8, 10 and 12 weeks of age. All phenotypes wereanalyzed at 19 weeks of age.

FIG. 15 is a line graph of IgG autoantibody titer (A_(450nm)) versus age(weeks) in MRL-lpr/lpr mice injected with control mIgG plasmid (□) orB7-H4Ig plasmid (▪).

FIG. 16 is a graph of proteinuria grade in MRL-lpr/lpr mice injectedwith control mIgG plasmid (□) or B7-H4Ig plasmid (□).

DETAILED DESCRIPTION OF THE INVENTION I. Definitions

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention pertains. All publications, patentapplications, patents, and other references mentioned herein areincorporated by reference in their entirety. In case of conflict, thepresent specification, including definitions, will control. In addition,the materials, methods, and examples are illustrative only and notintended to be limiting.

The term “effective amount” or “therapeutically effective amount” meansa dosage sufficient to provide treatment of the inflammatory response orautoimmune disease state being treated or to otherwise provide a desiredpharmacologic and/or physiologic effect. The precise dosage will varyaccording to a variety of factors such as subject-dependent variables(e.g., age, immune system health, etc.), the disease, and the treatmentbeing effected.

A “fragment” of a B7-H4 polypeptide is a fragment of the polypeptidethat is shorter than the full-length polypeptide. Generally, fragmentswill be five or more amino acids in length. An antigenic fragment hasthe ability to be recognized and bound by an antibody.

The terms “individual,” “individual,” “subject,” and “patient” are usedinterchangeably herein, and refer to a mammal, including, but notlimited to, rodents, simians, humans, mammalian farm animals, mammaliansport animals, and mammalian pets.

As used herein, “operably linked” with regard to nucleic acids meansincorporated into a genetic construct so that expression controlsequences effectively control expression of a coding sequence ofinterest.

The terms “polypeptide” and “protein” are used interchangeably and meanany peptide-linked chain of amino acids, regardless of length orpost-translational modification. Embodiments include B7-H4 polypeptideswith conservative substitutions. Conservative substitutions typicallyinclude substitutions within the following groups: glycine and alanine;valine, isoleucine, and leucine; aspartic acid and glutamic acid;asparagine, glutamine, serine and threonine; lysine, histidine andarginine; and phenylalanine and tyrosine.

The term “sH4” refers to soluble B7-H4 including biologically activefragments of the extracellular domain of B7-H4.

The term “soluble B7-H4 antagonist” or “sH4 antagonist” refers tocompounds that inhibit, reduce, or block the biological activity orexpression of soluble B7-H4. Suitable soluble B7-H4 antagonists include,but are not limited to antibodies and antibody fragments that bindsoluble B7-H4, B7-H4 or fragments thereof capable of antagonizingsoluble B7-H4, B7-H4 fusion proteins, protease inhibitors, small organiccompounds, antisense DNA, siRNA, and microRNA specific for nucleic acidsencoding sH4. In one embodiment, the soluble B7-H4 antagonist reduces orinhibits neutrophil-mediated inflammation.

As used herein, the term “treating” includes alleviating, preventingand/or eliminating one or more symptoms associated with inflammatoryresponses or an autoimmune disease.

Anti-Inflammatory Compositions

Compositions for inhibiting, reducing, or blocking the biologicalactivity or expression of soluble B7-H4 (also referred to as “sH4”) areprovided. In certain embodiments, the compositions include as an activeagent a sH4 antagonist in an amount effective to inhibit, reduce, ordecrease an inflammatory response. An exemplary inflammatory responseincludes, but is not limited to, neutrophil-mediated inflammatoryresponses.

A. sH4 Antagonists

Soluble B7-H4 antagonists include compounds that inhibit the expressionor biological activity of sH4. Soluble B7-H4 is approximately 50-kDa byWestern blot analysis, a size equal to entire extracellular domain ofmonomeric B7-H4 molecule in denatured condition (FIG. 1 b).

1. Protease Inhibitors

It is believed that sH4 is generated by enzymatic cleavage of the entireextracellular portion of B7-H4. 293T cells transfected with full lengthB7-H4 cDNA release sH4 into culture supernatant, and this secretion canbe inhibited by incubation with various proteases inhibitors. Thus, incertain embodiments, sH4 antagonists include protease inhibitors.Exemplary protease inhibitors include, but are not limited to, serineprotease inhibitors, cysteine protease inhibitors, aspartic proteaseinhibitors, and metalloprotease inhibitors. Specific protease inhibitorsinclude leupeptin, PMSF, AEBSF, aprotinin, chymostatin, antithrombinIII, 3,4-dichloroisocoumarin, TLCK, TPCK, DIFP, antipain,α2-macroglobulin, N-ethylmaleimide, E-64, chymostatin, pepstatin A,1,10-phenanthroline, phosphoramidon, and bestatin.

2. Inhibitory Nucleic Acids

sH4 containing only the IgV (FIG. 2 a) portion of the extracellulardomain is sufficient to exacerbate autoimmune diseases. In fact, B7-H4Vand B7-H4VC (FIG. 2 a) have similar effects in animal models, suggestingthat the binding site for its putative receptor is located in the IgVdomain, a result supported by a previous study using the B7-H4 IgVstructure based on a computer-generated model. A previous reportsuggests that B7-H4 is a GPI-anchoring protein which could become thesoluble form by detaching from an anchoring moiety. However, a recentstudy indicates that B7-H4 is a transmembrane protein. Several moleculesin the immunoglobulin superfamily have been shown to display solubleforms. These soluble molecules including CD80, CD86 and PD-1 are made bysplicing variants. Therefore, sH4 could be generated via alternativesplicing of B7-H4.

An inhibitory nucleic acid can specifically inhibit RNA splicing thatproduces a transcript encoding sH4 or specifically inhibit or reduce theexpression of RNA encoding sH4. Inhibitory nucleic acids include, butare not limited to, antisense DNA, triplex-forming oligonucleotides,external guide sequences, siRNA, and microRNA. Useful inhibitory nucleicacids include those that reduce the expression of RNA encoding sH4 by atleast 20, 30, 40, 50, 60, 70, 80, 90 or 95 percent compared to controls.Inhibitory nucleic acids and methods of producing them are well known inthe art. siRNA design software is available for example athttp://i.cs.hku.hk/˜sirna/software/sirna.php. Synthesis of nucleic acidsis well known see for example Molecular Cloning: A Laboratory Manual(Sambrook and Russel eds. 3^(rd) ed.) Cold Spring Harbor, N.Y. (2001).

3. Anti-sH4 Antibodies

Antibodies or antibody fragments that specifically bind to sH4 can beused to antagonize the biological activity of sH4. An exemplary antibodyis mAb hH4.3 (Choi, I. H. et al., J Immunol, 171:4650-4 (2003)). Methodsof producing antibodies are well known and within the ability of one ofordinary skill in the art.

For example, monoclonal antibodies (mAbs) and methods for theirproduction and use are described in Kohler and Milstein, Nature256:495-497 (1975); U.S. Pat. No. 4,376,110; Hartlow, E. et al.,Antibodies: A Laboratory Manual, Cold Spring Harbor Laboratory Press,Cold Spring Harbor, N.Y., 1988); Monoclonal Antibodies and Hybridomas: ANew Dimension in Biological Analyses, Plenum Press, New York, N.Y.(1980); H. Zola et al., in Monoclonal Hybridoma Antibodies: Techniquesand Applications, CRC Press, 1982)).

Anti-idiotypic antibodies are described, for example, in Idiotypy inBiology and Medicine, Academic Press, New York, 1984; ImmunologicalReviews Volume 79, 1984; Immunological Reviews Volume 90, 1986; Curr.Top. Microbiol., Immunol. Volume 119, 1985; Bona, C. et al., CRC Crit.Rev. Immunol., pp. 33-81 (1981); Jerme, N K, Ann. Immunol. 125C:373-389(1974); Jerne, N K, In: Idiotypes—Antigens on the Inside,Westen-Schnurr, I., ed., Editiones Roche, Basel, 1982, Urbain, J. etal., Ann. Immunol. 133D:179-(1982); Rajewsky, K. et al., Ann. Rev.Immunol. 1:569-607 (1983).

Certain embodiments provide antibodies, both polyclonal and monoclonal,reactive with novel epitopes of sH4 that are absent or masked in B7-H4.The antibodies may be xenogeneic, allogeneic, syngeneic, or modifiedforms thereof, such as humanized, single chain or chimeric antibodies.Antibodies may also be anti-idiotypic antibodies specific for theidiotype of an anti-sH4 antibody. The term “antibody” is also meant toinclude both intact molecules as well as fragments thereof that includethe antigen-binding site and are capable of binding to a sH4 epitope.These include Fab and F(ab′)₂ fragments which lack the Fc fragment of anintact antibody, and therefore clear more rapidly from the circulation,and may have less non-specific tissue binding than an intact antibody(Wahl et al., J. Nuc. Med. 24:316-325 (1983)). Also included are Fvfragments (Hochman, J. et al., Biochemistry, 12:1130-1135 (1973);Sharon, J. et al., Biochemistry, 15:1591-1594 (1976)). These variousfragments can be produced using conventional techniques such as proteasecleavage or chemical cleavage (see, e.g., Rousseaux et al., Meth.Enzymol., 121:663-69 (1986)).

Polyclonal antibodies are obtained as sera from immunized animals suchas rabbits, goats, rodents, etc. and may be used directly withoutfurther treatment or may be subjected to conventional enrichment orpurification methods such as ammonium sulfate precipitation, ionexchange chromatography, and affinity chromatography.

The immunogen may be any immunogenic portion of sH4. Preferredimmunogens include all or a part of the extracellular domain of humanB7-H4, where these residues contain the post-translation modifications,such as glycosylation, found on the native B7-H4. Immunogens includingthe extracellular domain are produced in a variety of ways known in theart, e.g., expression of cloned genes using conventional recombinantmethods, isolation from cells of origin, cell populations expressinghigh levels of B7-H4.

The mAbs may be produced using conventional hybridoma technology, suchas the procedures introduced by Kohler and Milstein, Nature, 256:495-97(1975), and modifications thereof (see above references). An animal,preferably a mouse is primed by immunization with an immunogen as aboveto elicit the desired antibody response in the primed animal.

B lymphocytes from the lymph nodes, spleens or peripheral blood of aprimed, animal are fused with myeloma cells, generally in the presenceof a fusion promoting agent such as polyethylene glycol (PEG). Any of anumber of murine myeloma cell lines are available for such use: theP3-NS1/1-Ag4-1, P3-x63-k0Ag8.653, Sp2/0-Ag14, or HL1-653 myeloma lines(available from the ATCC, Rockville, Md.). Subsequent steps includegrowth in selective medium so that unfused parental myeloma cells anddonor lymphocyte cells eventually die while only the hybridoma cellssurvive. These are cloned and grown and their supernatants screened forthe presence of antibody of the desired specificity, e.g. by immunoassaytechniques using the B7-H4-Ig fusion protein. Positive clones aresubcloned, e.g., by limiting dilution, and the mAbs are isolated.

Hybridomas produced according to these methods can be propagated invitro or in vivo (in ascites fluid) using techniques known in the art(see generally Fink et al., Prog. Clin. Pathol., 9:121-33 (1984)).Generally, the individual cell line is propagated in culture and theculture medium containing high concentrations of a single mAb can beharvested by decantation, filtration, or centrifugation.

The antibody may be produced as a single chain antibody or scFv insteadof the normal multimeric structure. Single chain antibodies include thehypervariable regions from an Ig of interest and recreate the antigenbinding site of the native Ig while being a fraction of the size of theintact Ig (Skerra, A. et al., Science, 240: 1038-1041 (1988); Pluckthun,A. et al., Methods Enzymol., 178: 497-515 (1989); Winter, G. et al.Nature, 349: 293-299 (1991); Bird et al., Science 242:423 (1988); Hustonet al. Proc. Natl. Acad. Sci. USA 85:5879 (1988); Jost C R et al., JBiol. Chem. 269:26267-26273 (1994); U.S. Pat. Nos. 4,704,692,4,853,871,4,94,6778, 5,260,203. In a preferred embodiment, the antibodyis produced using conventional molecular biology techniques.

Methods of using the antibodies to detect the presence of the epitopeare described in Coligan, J. E. et al., eds., Current Protocols inImmunology, Wiley-Interscience, New York 1991 (or current edition);Butt, W. R. (ed.) Practical Immunoassay The State of the Art, Dekker,N.Y., 1984; Bizollon, Ch. A., ed., Monoclonal Antibodies and New Trendsin Immunoassays, Elsevier, N.Y., 1984; Butler, J. E., ELISA (Chapter29), In: van Oss, C. J. et al., (eds), IMMUNOCHEMISTRY, Marcel Dekker,Inc., New York, 1994, pp. 759-803; Butler, J. E. (ed.), Immunochemistryof Solid-Phase Immunoassay, CRC Press, Boca Raton, 1991; Weintraub, B.,Principles of Radioimmunoassays, Seventh Training Course on RadioligandAssay Techniques, The Endocrine Society, March, 1986; Work, T. S. etal., Laboratory Techniques and Biochemistry in Molecular Biology, NorthHolland Publishing Company, NY, (1978) (Chapter by Chard, T., “AnIntroduction to Radioimmune Assay and Related Techniques”).

B. B7-H4 Fusion Proteins

B7-H4 fusion polypeptides have a first fusion partner including all or apart of a B7-H4 protein fused (i) directly to a second polypeptide or,(ii) optionally, fused to a linker peptide sequence that is fused to thesecond polypeptide. An exemplary fusion protein is described in Sica, G.L. et al. B7-H4, a molecule of the B7 family, negatively regulates Tcell immunity. Immunity 18, 849-61 (2003).

The B7-H4 fusion protein may be fused to a second polypeptide,preferably one or more domains of an Ig heavy chain constant region,preferably having an amino acid sequence corresponding to the hinge,C_(H2) and C_(H3) regions of a human immunoglobulin Cγ1 chain.

The B7-H4 fusion proteins can include full-length B7-H4 polypeptides, orcan contain a fragment of a full length B7-H4 polypeptide. In oneembodiment, the fusion protein contains a fragment of B7-H4. As usedherein, a fragment of B7-H4 refers to any subset of the polypeptide thatis a shorter polypeptide of the full length protein. Useful fragmentsare those that retain the ability to bind to their natural ligands. AB7-H4 polypeptide that is a fragment of full-length B7-H4 typically hasat least 20 percent, 30 percent, 40 percent, 50 percent, 60 percent, 70percent, 80 percent, 90 percent, 95 percent, 98 percent, 99 percent, 100percent, or even more than 100 percent of the ability to bind itsnatural ligand(s) as compared to full-length B7-H4.

One embodiment provides a fusion protein in which the first fusionpartner is the extracellular domain of a B7-H4 protein. B7-H4 nucleotideand protein sequence are found in GENBANK under accession numberAY280972. Additionally, B7-H4 is described in U.S. Pat. No. 6,891,030and where permissible, is incorporated by reference in its entirety. Thefusion protein can contain the entire extracellular domain of B7-H4 or afragment thereof that retains biological activity of B7-H4.

The first fusion partner of the fusion protein includes the membranedistal IgV domain and the membrane proximal IgC domain of B7-H4. Theconstruct can have at least 80%, 85%, 90%, 95%, or 99% sequence identityto:

(SEQ ID NO: 1) maslgqiifw siiniiiila gaialiigfg isgkhfitvttftsagnige dgtlsctfep diklngiviq wlkegikglvhefkegkddl sqqhemfrgr tavfadqvvv gnaslrlknvqltdagtytc yirtskgkgn anleyktgaf smpeinvdynasseslrcea prwfpqptva wasqvdqgan fsevsntsfelnsenvtmkv vsvlynvtin ntyscmiend iakatgdikv tdsevkrrsq lqllnsalso referred to as B7-H4VC.

In another embodiment, the first fusion partner of the fusion proteinincludes the IgV domain of B7-H4. The construct can have at least 80%,85%, 90%, 95%, or 99% sequence identity to:

(SEQ ID NO: 2) maslgqlifw siiniiiila gaialiigfg isgkhfitvttftsagnige dgtlsctfep diklngiviq wlkegikglvhefkegkddl sqqhemfrgr tavfadqvvv gnaslrlknvqltdagtytc yirtskgkgn anleyktgaf smpein also referred to as B7-H4V.

In a preferred embodiment, the fusion protein includes the extracellulardomain of B7-H4 or fragment thereof fused to an Ig Fc constant region.Recombinant B7-H4Ig fusion protein can be prepared by fusing the codingregion of the extracellular domain of B7-H4 to the Fe constant region ofmouse IgG2a as described previously (Chapoval et al. Methods Mol. Med.45:247-255 (2000)).

The disclosed fusion proteins can be isolated using standard molecularbiology techniques. For example, an expression vector containing a DNAsequence encoding B7-H4Ig is transfected into 293 cells by calciumphosphate precipitation and cultured in serum-free DMEM. The supernatantis collected at 72 h and the fusion protein is purified by Protein GSEPHAROSE® columns (Pharmacia, Uppsala, Sweden).

Variants of B7-H4 can also be used to produce a fusion protein thatreduces, inhibits or blocks the biological function of sH4. As usedherein, a “variant” B7-H4 polypeptide contains at least one amino acidsequence alteration as compared to the amino acid sequence of thecorresponding wild-type B 7-H4 polypeptide (e.g., a polypeptide havingthe amino acid sequence set forth in Accession No. AY280972). An aminoacid sequence alteration can be, for example, a substitution, adeletion, or an insertion of one or more amino acids.

Variants of B7-H4 can have the same activity, substantially the sameactivity, or different activity than wildtype B7-H4. Substantially thesame activity means that the variant is able to suppress T cellactivation.

It will be appreciated that variants of the extracellular domain ofB7-H4 can have at least 80% sequence identity with the extracellulardomain of wild-type B7-H4 (i.e., Accession No. AY280972), typically atleast 85%, more typically, at least 90%, even more typically, at least95% sequence identity to the extracellular domain of B7-H4. In oneembodiment, the fusion protein includes the extracellular domain ofB7-H4 that is identical to the extracellular domain of B7-H4 inAccession No. AY280972.

Percent sequence identity can be calculated using computer programs ordirect sequence comparison. Preferred computer program methods todetermine identity between two sequences include, but are not limitedto, the GCG program package, PASTA, BLASTP, and TBLASTN (see, e.g., D.W. Mount, 2001, Bioinformatics: Sequence and Genome Analysis, ColdSpring Harbor Laboratory Press, Cold Spring Harbor, N.Y.). The BLASTPand TBLASTN programs are publicly available from NCBI and other sources.The well-known Smith Waterman algorithm may also be used to determineidentity.

Exemplary parameters for amino acid sequence comparison include thefollowing: 1) algorithm from Needleman and Wunsch J. Mol. Biol.,48:443-453 (1970); 2) BLOSSUM62 comparison matrix from Hentikoff andHentikoff Proc. Natl. Acad. Sci. U.S.A., 89:10915-10919 (1992); 3) gappenalty=12; and 4) gap length penalty=4. A program useful with theseparameters is publicly available as the “gap” program (Genetics ComputerGroup, Madison, Wis.). The aforementioned parameters are the defaultparameters for polypeptide comparisons (with no penalty for end gaps).

Alternatively, polypeptide sequence identity can be calculated using thefollowing equation: % identity=(the number of identicalresidues)/(alignment length in amino acid residues)*100. For thiscalculation, alignment length includes internal gaps but does notinclude terminal gaps.

Amino acid substitutions can be made using any amino acid or amino acidanalog. For example, substitutions can be made with any of thenaturally-occurring amino acids (e.g., alanine, aspartic acid,asparagine, arginine, cysteine, glycine, glutamic acid, glutamine,histidine, leucine, valine, isoleucine, lysine, methionine, praline,threonine, serine, phenylalanine, tryptophan, or tyrosine).

Amino acid substitutions in B7-H4 fusion proteins polypeptides may beconservative substitutions. As used herein, “conservative” amino acidsubstitutions are substitutions wherein the substituted amino acid hassimilar structural or chemical properties. “Non-conservative” amino acidsubstitutions are those in which the charge, hydrophobicity, or bulk ofthe substituted amino acid is significantly altered. Non-conservativesubstitutions will differ more significantly in their effect onmaintaining (a) the structure of the peptide backbone in the area of thesubstitution, for example, as a sheet or helical conformation, (b) thecharge or hydrophobicity of the molecule at the target site, or (c) thebulk of the side chain. Conservative substitutions typically includesubstitutions within the following groups; glycine and alanine; valine,isoleucine, and leucine; aspartic acid and glutamic acid; asparagine,glutamine, serine and threonine; lysine, histidine and arginine; andphenylalanine and tyrosine.

The disclosed fusion proteins and variants thereof preferably competewith sH4 to inhibit the biological activity of sH4, for example bybinding to a common receptor. The receptor is typically a receptor on animmune cell that binds both sH4 and B7-H4. The variants of theextracellular domain of B7-H4 include conservative variants andnon-conservative variants that increase the ability to of the fusionprotein to compete with sH4 and thereby reduce the biological activityof sH4.

Also provided is a dimeric or trimeric fusion protein which is a dimeror trimer of the above fusion proteins. Preferably, the chains aretandemly linked via disulfide bonds or other interchain covalent bonds.

In a preferred dimeric fusion protein, the dimer results from thecovalent bonding of Cys residue in the CH regions of two of the Ig heavychains that are the same Cys residues that are disulfide linked indimerized normal Ig H chains.

Suitable fusion proteins may include a multimer of two or more repeatsof the first fusion partner linked end to end, directly or with a linkersequence between one or more monomers.

C. Pharmaceutical Compositions

Pharmaceutical compositions including sH4 antagonists, and vectorscontaining the same are provided. The pharmaceutical compositions may befor administration by oral, parenteral (intramuscular, intraperitoneal,intravenous (IV) or subcutaneous injection), transdermal (eitherpassively or using iontophoresis or electroporation), transmucosal(nasal, vaginal, rectal, or sublingual) routes of administration orusing bioerodible inserts and can be formulated in dosage formsappropriate for each route of administration.

1. Formulations for Parenteral Administration

In a preferred embodiment, the peptides are administered in an aqueoussolution, by parenteral injection. The formulation may also be in theform of a suspension or emulsion. In general, pharmaceuticalcompositions are provided including effective amounts of a sH4antagonist, or derivative products, and optionally includepharmaceutically acceptable diluents, preservatives, solubilizers,emulsifiers, adjuvants and/or carriers. Such compositions includediluents sterile water, buffered saline of various buffer content (e.g.,Tris-HCl, acetate, phosphate), pH and ionic strength; and optionally,additives such as detergents and solubilizing agents (e.g., TWEEN 20,TWEEN 80, Polysorbate 80), anti-oxidants (e.g., ascorbic acid, sodiummetabisulfite), and preservatives (e.g., Thimersol, benzyl alcohol) andbulking substances (e.g., lactose, mannitol). Examples of non-aqueoussolvents or vehicles are propylene glycol, polyethylene glycol,vegetable oils, such as olive oil and corn oil, gelatin, and injectableorganic esters such as ethyl oleate. The formulations may be lyophilizedand redissolved/resuspended immediately before use. The formulation maybe sterilized by, for example, filtration through a bacteria retainingfilter, by incorporating sterilizing agents into the compositions, byirradiating the compositions, or by heating the compositions.

2. Formulations for Enteral Administration

sH4 antagonists can be formulated for oral delivery. Oral solid dosageforms are described generally in Remington's Pharmaceutical Sciences,18th Ed. 1990 (Mack Publishing Co. Easton Pa. 18042) at Chapter 89.Solid dosage forms include tablets, capsules, pills, troches orlozenges, cachets, pellets, powders, or granules or incorporation of thematerial into particulate preparations of polymeric compounds such aspolylactic acid, polyglycolic acid, etc. or into liposomes. Suchcompositions may influence the physical state, stability, rate of invivo release, and rate of in vivo clearance of the present proteins andderivatives. See, e.g., Remington's Pharmaceutical Sciences, 18th Ed.(1990, Mack Publishing Co., Easton, Pa. 18042) pages 1435-1712 which areherein incorporated by reference. The compositions may be prepared inliquid form, or may be in dried powder (e.g., lyophilized) form.Liposomal or proteinoid encapsulation may be used to formulate thecompositions (as, for example, proteinoid microspheres reported in U.S.Pat. No. 4,925,673). Liposomal encapsulation may be used and theliposomes may be derivatized with various polymers (e.g., U.S. Pat. No.5,013,556). See also Marshall, K. In: Modern Pharmaceutics Edited by G.S. Banker and C. T. Rhodes Chapter 10, 1979. In general, the formulationwill include the peptide (or chemically modified forms thereof) andinert ingredients which protect peptide in the stomach environment, andrelease of the biologically active material in the intestine.

The polypeptide antagonists may be chemically modified so that oraldelivery of the derivative is efficacious. Generally, the chemicalmodification contemplated is the attachment of at least one moiety tothe component molecule itself, where said moiety permits (a) inhibitionof proteolysis; and (b) uptake into the blood stream from the stomach orintestine. Also desired is the increase in overall stability of thecomponent or components and increase in circulation time in the body.PEGylation is a preferred chemical modification for pharmaceuticalusage. Other moieties that may be used include: propylene glycol,copolymers of ethylene glycol and propylene glycol, carboxymethylcellulose, dextran, polyvinyl alcohol, polyvinyl pyrrolidone,polyproline, poly-1,3-dioxolane and poly-1,3,6-tioxocane [see, e.g.,Abuchowski and Davis (1981) “Soluble Polymer-Enzyme Adducts,” in Enzymesas Drugs. Hocenberg and Roberts, eds. (Wiley-Interscience: New York,N.Y.) pp. 367-383; and Newmark, et al. (1982) J. Appl. Biochem.4:185-189].

Another embodiment provides liquid dosage forms for oral administration,including pharmaceutically acceptable emulsions, solutions, suspensions,and syrups, which may contain other components including inert diluents;adjuvants such as wetting agents, emulsifying and suspending agents; andsweetening, flavoring, and perfuming agents.

Controlled release oral formulations may be desirable. The sH4antagonists can be incorporated into an inert matrix which permitsrelease by either diffusion or leaching mechanisms, e.g., gums. Slowlydegenerating matrices may also be incorporated into the formulation.Another form of a controlled release is based on the Oros therapeuticsystem (Alza Corp.), i.e. the drug is enclosed in a semipermeablemembrane which allows water to enter and push drug out through a singlesmall opening due to osmotic effects. For oral formulations, thelocation of release may be the stomach, the small intestine (theduodenum, the jejunum, or the ileum), or the large intestine.Preferably, the release will avoid the deleterious effects of thestomach environment, either by protection of the peptide (or derivative)or by release of the peptide (or derivative) beyond the stomachenvironment, such as in the intestine. To ensure full gastric resistancea coating impermeable to at least pH 5.0 is essential. Examples of themore common inert ingredients that are used as enteric coatings arecellulose acetate trimellitate (CAT), hydroxypropylmethylcellulosephthalate (HPMCP), HPMCP 50, HPMCP 55, polyvinyl acetate phthalate(PVAP), Eudragit L30D, Aquateric, cellulose acetate phthalate (CAP),Eudragit L, Eudragit S, and Shellac. These coatings may be used as mixedfilms.

3. Topical Delivery Formulations

Compositions can be applied topically. This does not work well for mostpeptide formulations, although it can be effective especially if appliedto the lungs, nasal, oral (sublingual, buccal), vaginal, or rectalmucosa. The sH4 antagonists can be delivered to the lungs while inhalingand traverses across the lung epithelial lining to the blood stream whendelivered either as an aerosol or spray dried particles having anaerodynamic diameter of less than about 5 microns.

A wide range of mechanical devices designed for pulmonary delivery oftherapeutic products can be used, including but not limited tonebulizers, metered dose inhalers, and powder inhalers, all of which arefamiliar to those skilled in the art. Some specific examples ofcommercially available devices are the Ultravent nebulizer (MallinckrodtInc., St. Louis, Mo.); the Acorn II nebulizer (Marquest MedicalProducts, Englewood, Colo.); the Ventolin metered dose inhaler (GlaxoInc., Research Triangle Park, N.C.); and the Spinhaler powder inhaler(Fisons Corp., Bedford, Mass.). Nektar, Alkermes and Mannkind all haveinhalable insulin powder preparations approved or in clinical trialswhere the technology could be applied to the formulations describedherein.

Formulations for administration to the mucosa will typically be spraydried drug particles, which may be incorporated into a tablet, gel,capsule, suspension or emulsion. Standard pharmaceutical excipients areavailable from any formulator. Oral formulations may be in the form ofchewing gum, gel strips, tablets or lozenges.

Transdermal formulations may also be prepared. These will typically beointments, lotions, sprays, or patches, all of which can be preparedusing standard technology. Transdermal formulations will require theinclusion of penetration enhancers.

4. Controlled Delivery Polymeric Matrices

Controlled release polymeric devices can be made for long term releasesystemically following implantation of a polymeric device (rod,cylinder, film, disk) or injection (microparticles). The matrix can bein the form of microparticles such as microspheres, where peptides aredispersed within a solid polymeric matrix or microcapsules, where thecore is of a different material than the polymeric shell, and thepeptide is dispersed or suspended in the core, which may be liquid orsolid in nature. Unless specifically defined herein, microparticles,microspheres, and microcapsules are used interchangeably. Alternatively,the polymer may be cast as a thin slab or film, ranging from nanometersto four centimeters, a powder produced by grinding or other standardtechniques, or even a gel such as a hydrogel.

Either non-biodegradable or biodegradable matrices can be used fordelivery of sH4 antagonists, although biodegradable matrices arepreferred. These may be natural or synthetic polymers, althoughsynthetic polymers are preferred due to the better characterization ofdegradation and release profiles. The polymer is selected based on theperiod over which release is desired. In some cases linear release maybe most useful, although in others a pulse release or “bulk release” mayprovide more effective results. The polymer may be in the form of ahydrogel (typically in absorbing up to about 90% by weight of water),and can optionally be crosslinked with multivalent ions or polymers.

The matrices can be formed by solvent evaporation, spray drying, solventextraction and other methods known to those skilled in the art.Bioerodible microspheres can be prepared using any of the methodsdeveloped for making microspheres for drug delivery, for example, asdescribed by Mathiowitz and Langer, J. Controlled Release 5, 13-22(1987); Mathiowitz, et al., Reactive Polymers 6, 275-283 (1987); andMathiowitz, et al., J. Appl. Polymer Sci. 35, 755-774 (1988).

The devices can be formulated for local release to treat the area ofimplantation or injection—which will typically deliver a dosage that ismuch less than the dosage for treatment of an entire body—or systemicdelivery. These can be implanted or injected subcutaneously, into themuscle, fat, or swallowed.

III. Methods of Manufacture

As discussed above and in the examples, polypeptide sH4 antagonists,nucleic acid constructs encoding sH4 antagonists, B7-H4 or variantsthereof can be produced using standard molecular biology protocols knownin the art. See for example, Molecular Cloning: A Laboratory Manual(Sambrook and Russel eds. 3^(rd) ed.) Cold Spring Harbor, N.Y. (2001).Alternatively, B7-H4, sH4, antagonists or agonists thereof, or variantsthere of can be isolated and purified from an individual expressing themusing conventional biochemical techniques.

IV. Inflammatory Response Treatment and Detection

A. Diagnostics

Soluble B7-H4 is found in sera of approximately two-thirds of the R^(A)and one-third of the SLE patients sampled and the concentration of sH4correlates closely with the severity of RA. In an experimental model ofRA and SLE, the effect of sH4 was recapitulated, and it was demonstratedthat sH4 acts as a decoy to block suppressive functions of endogenousB7-H4, leading to exacerbation of systemic autoimmune diseases (seeExamples). The results demonstrate a role of sH4 in the pathogenesis ofsystemic autoimmune diseases.

An inflammatory response in an individual can be detected by quantifyingthe amount of sH4 in a biological sample of the individual, wherein anelevated amount of sH4 in the individual's biological sample compared toa control (single or more preferably pooled or averaged values of normalindividuals in same assay) is indicative of an inflammatory response. Abiological sample includes tissue or biological fluid such as a fluidfrom the individual, for example, blood, plasma, saliva, lymph,cerebrospinal fluid, or sputum. A control refers to a biological samplefrom an individual not experiencing an inflammatory response such as anautoimmune disease.

The amount of sH4 in a sample can be determined using conventionaltechniques such as enzyme-linked immunosorbent assays, massspectrometry, spectrophotometry, or a combination thereof.

The severity of an inflammatory response or an autoimmune disease can bedetected or assessed by quantifying the level of sH4 in an individual'sbiological sample and correlating the amount of sH4 in the individual'sbiological sample with amount(s) of sH4 indicative of different stagesof an inflammatory response or autoimmune disease. The amounts of sH4with different stages of inflammatory disease or different levels ofseverity can be predetermined by quantifying sH4 in patients atdifferent stages of inflammatory disease, or with different severity ofdisease. For example, with RA the following classification for severityis typically employed: Class I: No restriction of ability to performnormal activities; Class II: Moderate restriction, but with an abilityto perform most activities of daily living; Class III: Markedrestriction, with an inability to perform most activities of dailyliving and occupation; and Class IV: Incapacitation with confinement tobed or wheelchair. Levels of sH4 can be deter mined in patients fromeach classification to produce a reference level of sH4 that can becorrelated with the specific severity level.

Alternatively, the amount of sH4 can be correlated to levels ofneutrophils. In individuals with inflammatory responses or autoimmunedisease, sH4 is elevated as are levels of neutrophils. Thus, sH4 levelsin an individual can be predictive of neutrophil levels.

Representative inflammatory responses or autoimmune diseases that can bedetected or assessed for severity include, but are not limited to,rheumatoid arthritis, systemic lupus erythematosus, alopecia greata,anklosing spondylitis, antiphospholipid syndrome, autoimmune Addison'sdisease, autoimmune hemolytic anemia, autoimmune hepatitis, autoimmuneinner ear disease, autoimmune lymphoproliferative syndrome (alps),autoimmune thrombocytopenic purpura (ATP), Behcet's disease, bullouspemphigoid, cardiomyopathy, celiac sprue-dermatitis, chronic fatiguesyndrome immune deficiency, syndrome (CFIDS), chronic inflammatorydemyelinating polyneuropathy, cicatricial pemphigoid, cold agglutinindisease, Crest syndrome, Crohn's disease, Dego's disease,dermatomyositis, dermatomyositis juvenile, discoid lupus, essentialmixed cryoglobulinemia, fibromyalgia—fibromyositis, grave's disease,guillain-barre, hashimoto's thyroiditis, idiopathic pulmonary fibrosis,idiopathic thrombocytopenia purpura (ITP), Iga nephropathy, insulindependent diabetes (Type I), juvenile arthritis, Meniere's disease,mixed connective tissue disease, multiple sclerosis, myasthenia gravis,pemphigus vulgaris, pernicious anemia, polyarteritis nodosa,polychondritis, polyglancular syndromes, polymyalgia rheumatica,polymyositis and dermatomyositis, primary agammaglobulinemia, primarybiliary cirrhosis, psoriasis, Raynaud's phenomenon, Reiter's syndrome,rheumatic fever, sarcoidosis, scleroderma, Sjogren's syndrome, stiff-mansyndrome, Takayasu arteritis, temporal arteritis/giant cell arteritis,ulcerative colitis, uveitis, vasculitis, vitiligo, and Wegener'sgranulomatosis.

B. Methods of Treating Inflammatory Responses

Chronic and persistent inflammation is a major cause of the pathogenesisand progression of systemic autoimmune diseases such as rheumatoidarthritis (RA) and systemic lupus erythematosus (SLE). sH4 acts as adecoy molecule to block endogenous B7-H4. B7-H4 inhibits cell cycleprogression of T cells in the presence of antigen stimulation. B7-H4 caninhibit innate immunity by suppressing proliferation of neutrophilprogenitors. It is believed that elevated levels of sH4 block theinhibitory effect of endogenous B7-H4.

Therefore, an inflammatory response can be treated by interfering withthe biological activity of sH4 in vivo, for example, by administering toan individual in need thereof an effective amount of a sH4 antagonist toinhibit or decrease one or more symptoms of the disease, which may beindicated by a decrease in neutrophil levels. Interference of sH4biological activity can be accomplished by down regulating expression ofsH4, removing 414, conjugating sH4 with a binding agent in vivo, forexample an antibody, increasing the endogenous levels of B7-H4,administering B7-H4 fusion proteins, or a combination thereof.

1. Down-Regulation of sH4 Expression

One method for treating a inflammatory response or autoimmune disease isby administering to an individual in need thereof an mount of inhibitorynucleic acid specific for a nucleic acid encoding sH4 effective toreduce or inhibit the inflammatory response. The inhibitory nucleic acidcan be antisense DNA, siRNA, microRNA, or a combination thereof.Alternatively, the inhibitory nucleic acid can be specific for aprotease that cleaves B7-H4 to produce sH4. In a preferred embodiment,the inhibitory nucleic acid downregulates sH4 expression without havinga statistically significant effect on B7-H4 expression. In certainaspects, the downregulation of sH4 causes a decrease in the neutrophilpopulation.

2. Removal of sH4

Another method for treating an inflammatory response or autoimmunedisorder in an individual is by removing sH4 from an individual's bloodor plasma. Soluble B7-H4 can be removed using well known techniques suchas ultrapheresis, apheresis, or dialysis. In one embodiment, blood orplasma is removed from an individual. Soluble B7-H4 is selectivelyremoved from the blood or plasma ex vivo. Selective removal of sH4 canbe achieved using filters having specific molecular weight cutoffs thatallow sH4 to pass while other components are retained.

Alternatively, the blood or plasma can be contacted with binding agentsspecific for sH4. The binding agents can be immobilized on a substrate.Suitable binding agents include, but are not limited to antibodies orantigen-binding antibody fragments specific for sH4 or natural ligandsof sH4. The binding agents specifically bind sH4 and capture the sH4,thereby removing it from the blood or plasma. The treated blood orplasma is then returned to the individual.

3. Inactivation of sH4

Another method for treating an inflammatory response or autoimmunedisease is by administering to an individual in need thereof, a sH4binding agent in an amount effective to reduce or inhibit theinflammatory response. A representative binding agent includes, but isnot limited to an antibody or antigen-binding fragment thereof thatinhibits or reduces a biological activity of sH4. A representativeantibody is mAb hH4.3. It will be appreciated that small molecules canbe used to bind and inactive sH4 in vivo.

4. Over-Expression of B7-H4

Over-expression of B7-H4 can be used to compete with endogenous sH4 andcan therefore be an effective means for treating inflammatory responsesand autoimmune diseases or disorders. Overexpression of B7-H4 can beaccomplished by stimulating endogenous B7-H4 to increase expression.Alternatively, B7-H4 can be administered as a bolus to an individual inneed thereof to temporarily increase serum levels of B7-H4.

Another method for treating an inflammatory response or autoimmunedisease is by administering to an individual in need thereof a nucleicacid construct encoding B7-H4, or a functional fragment thereof.Functional fragment means a 87-H4 fragment that interferes with,inhibits or reduces sH4 biological activity.

In another embodiment, B7-H4 fusion protein can be administered to anindividual in need thereof in an amount effective to reduce or inhibitsH4-mediated inflammation or a symptom thereof. The B7-H4 fusionproteins are discussed above. Alternatively, a nucleic acid constructencoding the B7-H4 fusion can be administered to an individual in needthereof wherein the nucleic acid construct is expressed in theindividual and produces B7-H4 fusion protein in amounts effective toreduce or inhibit sH4 biological function.

5. Gene Delivery

Nucleic acids encoding sH4 antagonists can be administered to anindividual in need thereof in an amount effective to treat aninflammatory response or autoimmune disease. DNA delivery involvesintroduction of a “foreign” DNA into a cell and ultimately, into a liveanimal. Gene delivery can be achieved using viral vectors or non-viralvectors. One approach includes nucleic acid transfer into primary cellsin culture followed by autologous transplantation of the ex vivotransformed cells into the individual, either systemically or into aparticular organ or tissue.

Nucleic acid therapy can be accomplished by direct transfer of afunctionally active DNA into mammalian somatic tissue or organ in vivo.DNA transfer can be achieved using a number of approaches describedbelow. These systems can be tested for successful expression in vitro byuse of a selectable marker (e.g., G418 resistance) to select transfectedclones expressing the DNA, followed by detection of the presence of theB7-H4 expression product (after treatment with the inducer in the caseof an inducible system) using an antibody to the product in anappropriate immunoassay. Efficiency of the procedure, including DNAuptake, plasmid integration and stability of integrated plasmids, can beimproved by linearizing the plasmid DNA using known methods, andco-transfection using high molecular weight mammalian DNA as a“carrier”.

Retroviral-mediated human therapy utilizes amphotrophic,replication-deficient retrovirus systems (Weiss and Taylor, Cell,82:531-533 (1995)). Such vectors have been used to introduce functionalDNA into human cells or tissues, for example, the adenosine deaminasegene into lymphocytes, the NPT-II gene and the gene for tumor necrosisfactor into tumor infiltrating lymphocytes. Retrovirus-mediated genedelivery generally requires target cell proliferation for gene transfer(Bordignon et al. Science 270:470-475 (1995)). This condition is met bycertain of the preferred target cells into which the present DNAmolecules are to be introduced, i.e., actively growing tumor cells. Genetherapy of cystic fibrosis using transfection by plasmids using any of anumber of methods and by retroviral vectors has been described byCollins et al., U.S. Pat. No. 5,240,846.

The DNA molecules encoding the B7-H4 polypeptides or fusion proteins maybe packaged into retrovirus vectors using packaging cell lines thatproduce replication-defective retroviruses, as is well-known in the art(see, for example Stone, D. et al. J. Endocrinology, 164:103-118(2000)). Additional viruses for gene delivery are described in Reynoldset al. Molecular Medicine Today, 5:25-31 (1999)).

Other virus vectors may also be used, including recombinant adenoviruses(Murphy et al. Proc Natl Acad Scii 94:13921-13926 (1997)), herpessimplex virus (HSV) for neuron-specific delivery and persistence(Lowenstein et al. Brain Res. Molec. Brain Res, 30:169-175 (1995)).Advantages of adenovirus vectors for human gene therapy include the factthat recombination is rare, no human malignancies are known to beassociated with such viruses, the adenovirus genome is double strandedDNA which can be manipulated to accept foreign genes of up to 7.5 kb insize, and live adenovirus is a safe human vaccine organisms.Adeno-associated virus is also useful for human therapy (Samulski, R. J.et al., EMBO J. 10:3941 (1991).

Another vector which can express the disclosed DNA molecule and isuseful in the present therapeutic setting, particularly in humans, isvaccinia virus, which can be rendered non-replicating (Peplinkski, G. R.et al. Surgical Oncology Clinics of North America, 7575-588 1998)).Descriptions of recombinant vaccinia viruses and other virusescontaining heterologous DNA and their uses in immunization and DNAtherapy are reviewed in: Moss, B., Curr. Opin. Genet. Dev. 3:86-90(1993); Moss, B. Biotechnology 20: 345-362 (1992); Moss, B., Curr TopMicrobial Immunol 158:25-38 (1992); Moss, B., Science 252:1662-1667(1991); Piccini, A et al., Adv. Virus Res. 34:43-64 (1988); Moss, B. etal., Gene Amplif Anal 3:201-213 (1983).

In addition to naked DNA or RNA, or viral vectors, engineered bacteriamay be used as vectors. A number of bacterial strains includingSalmonella, BCG and Listeria monocytogenes (LM) (Hoiseth & Stocker,Nature 291, 238-239 (1981); Poirier, T P et al. J. Exp. Med. 168, 25-32(1988); (Sadoff, J. C., et al., Science 240, 336-338 (1988); Stover, C.K., et al., Nature 351, 456-460 (1991); Aldovini, A. et al., Nature 351,479-482 (1991); Schafer, R., et al., J. Immunol. 149, 53-59 (1992);Ikonomidis, G. et al., J. Exp. Med. 180, 2209-2218 (1994)). Theseorganisms display two promising characteristics for use as vaccinevectors: (1) enteric routes of infection, providing the possibility oforal vaccine delivery; and (2) infection of monocytes/macrophagesthereby targeting antigens to professional APCs.

In addition to virus-mediated gene transfer in vivo, physical meanswell-known in the art can be used for direct transfer of DNA, includingadministration of plasmid DNA (Wolff et al., Science, 247:1465-1468(1990); Hickman, M. A, et al. Hum. Gene Ther., 5:1477-1483 (1994)) andparticle-bombardment mediated gene transfer (O'Brien, J. et al. BrainRes Brain Res Protco, 10:12-15 (2002)). Furthermore, electroporation, awell-known means to transfer genes into cell in vitro, can be used totransfer DNA molecules to tissues in vivo (Titomirov, A. V. et al.,Biochim. Biophys. Acta 1088:131 ((1991)).

“Carrier mediated gene transfer” has also been described (Wu, C. H. etal., J. Biol. Chem. 264:16985 (1989); Wu, G. Y. et al., J. Biol. Chem.263:14621 (1988); Soriano, P. et al., Proc. Natl. Acad. Sci. USA 80:7128(1983); Wang, C-Y. et al., Proc. Natl. Acad. Sci. USA 84:7851 (1982);Wilson, J. M. et al., J. Biol. Chem. 267:963 (1992)). Preferred carriersare targeted liposomes (Liu et al. Curr Med Chem, 10:1307-1315 (2003))such as immunoliposomes, which can incorporate acylated mAbs into thelipid bilayer. Polycations such as asialoglycoprotein/polylysine (Wu etal., 1989, supra) may be used, where the conjugate includes a moleculewhich recognizes the target tissue (e.g., asialoorosomucoid for liver)and a DNA binding compound to bind to the DNA to be transfected.Polylysine is an example of a DNA binding molecule which binds DNAwithout damaging it. This conjugate is then complexed with plasmid DNAfor transfer.

Plasmid DNA used for transfection or microinjection may be preparedusing methods well-known in the art, for example using the Quiagenprocedure (Quiagen), followed by DNA purification using known methods,such as the methods exemplified herein.

6. Combination Therapy

The disclosed compositions can be administered to a subject in needthereof alone or in combination with one or more additional therapeuticagents including, but not limited to immunosuppressive agents, e.g.,antibodies against other lymphocyte surface markers (e.g., CD40) oragainst cytokines, other fusion proteins, e.g., CTLA41g, or otherimmunosuppressive drugs (e.g., cyclosporin A, FK506-like compounds,rapamycin compounds, or steroids), anti-proliferatives, cytotoxicagents, or other compounds that may assist in immunosuppression.

As used herein the term “rapamycin compound” includes the neutraltricyclic compound rapamycin, rapamycin derivatives, rapamycin analogs,and other macrolide compounds which are thought to have the samemechanism of action as rapamycin (e.g., inhibition of cytokinefunction). The language “rapamycin compounds” includes compounds withstructural similarity to rapamycin, e.g., compounds with a similarmacrocyclic structure, which have been modified to enhance theirtherapeutic effectiveness. Exemplary Rapamycin compounds are known inthe art (See, e.g. WO 95122972, WO 95116691, WO 95104738, U.S. Pat. Nos.6,015,809; 5,989,591; U.S. Pat. Nos. 5,567,709; 5,559,112; 5,530,006;5,484,790; 5,385,908; 5,202,332; 5,162,333; 5,780,462; 5,120,727).

The language “FK506-like compounds” includes FK506, and FK506derivatives and analogs, e.g., compounds with structural similarity toFK506, e.g., compounds with a similar macrocyclic structure which havebeen modified to enhance their therapeutic effectiveness. Examples ofFK506-like compounds include, for example, those described in WO00101385. Preferably, the language “rapamycin compound” as used hereindoes not include FK506-like compounds.

Other suitable therapeutics include, but are not limited to,anti-inflammatory agents. The anti-inflammatory agent can benon-steroidal, steroidal, or a combination thereof. One embodimentprovides oral compositions containing about 1% (w/w) to about 5% (w/w),typically about 2.5% (w/w) or an anti-inflammatory agent. Representativeexamples of non-steroidal anti-inflammatory agents include, withoutlimitation, oxicams, such as piroxicam, isoxicam, tenoxicam, sudoxicam;salicylates, such as aspirin, disalcid, benorylate, trilisate, safapryn,solprin, diflunisal, and fendosal; acetic acid derivatives, such asdiclofenac, fenclofenac, indomethacin, sulindac, tolmetin, isoxepac,furofenac, tiopinac, zidometacin, acematacin, fentiazac, zomepirac,clindanac, oxepinac, felbinac, and ketorolac; fenamates, such asmefenamic, meclofenamic, flufenamic, niflumic, and tolfenamic acids;propionic acid derivatives, such as ibuprofen, naproxen, benoxaprofen,flurbiprofen, ketoprofen, fenoprofen, fenbufen, indopropfen, pirprofen,carprofen, oxaprozin, pranoprofen, miroprofen, tioxaprofen, suprofen,alminoprofen, and tiaprofenic; pyrazoles, such as phenylbutazone,oxyphenbutazone, feprazone, azapropazone, and trimethazone. Mixtures ofthese non-steroidal anti-inflammatory agents may also be employed.

Representative examples of steroidal anti-inflammatory drugs include,without limitation, corticosteroids such as hydrocortisone,hydroxyl-triamcinolone, alpha-methyl dexamethasone,dexamethasone-phosphate, beclomethasone dipropionates, clobetasolvalerate, desonide, desoxymethasone, desoxycorticosterone acetate,dexamethasone, dichlorisone, diflorasone diacetate, diflucortolonevalerate, fluadrenolone, fluclorolone acetonide, fludrocortisone,flumethasone pivalate, fluosinolone acetonide, fluocinonide, flucortinebutylesters, fluocortolone, fluprednidene (fluprednylidene) acetate,flurandrenolone, halcinonide, hydrocortisone acetate, hydrocortisonebutyrate, methylprednisolone, triamcinolone acetonide, cortisone,cortodoxone, flucetonide, fludrocortisone, difluorosone diacetate,fluradrenolone, fludrocortisone, difluorosone diacetate, fluradrenoloneacetonide, medrysone, amcinafel, amcinafide, betamethasone and thebalance of its esters, chloroprednisone, chlorprednisone acetate,clocortelone, clescinolone, dichlorisone, diflurprednate, flucloronide,flunisolide, fluoromethalone, fluperolone, fluprednisolone,hydrocortisone valerate, hydrocortisone cyclopentylpropionate,hydrocortamate, meprednisone, paramethasone, prednisolone, prednisone,beclomethasone dipropionate, triamcinolone, and mixtures thereof.

V. Transgenic Animals

Transgenic non-human animals that do not express B7-H4 or have reducedexpression are useful in screening and testing. The endogenous B7-H4gene and alleles can be disrupted by inserting a genetic element intothe gene to prevent expression. Preferably, the endogenous B7-H4 gene isdeleted using homologous recombination. Representative non-humantransgenic animals include mice or other rodents, sheep, goats, cows,pigs, and non-human primates.

The transgenic animals can be used to as research tools to study howB7-H4 modulates the immune system, in particular how B7-H4 suppressesimmune responses. For example, the transgenic animals can be used toscreen for compounds that mimic endogenous B7-H4 biological activity orfor compounds that interact with soluble B7-H4.

The present invention will be further understood by reference to thefollowing non-limiting examples.

EXAMPLES Example 1 Generation of B7-H4KO Mice

Mice

6-8-week-old C57BL16 (B6) mice were obtained from the JacksonLaboratory. RAG-1 KO mice were purchased from Taconic Farms. Both femaleand male mice were used for the experiments. All mice were housed underspecific pathogen-free conditions in the Johns Hopkins Animal Facilitywith all protocols approved by the Institutional Animal Care and UseCommittee. The general strategy to generate gene KO mice by homologousrecombination was described by Dong, H. et al., Immunity 20:327-336(2004); Tamada, K. et al., J Immunol., 168, 4832-4835 (2002). Togenerate B7-H4 KO mice, a 5.09 kb DNA fragment upstream of the IgVdomain (exon 3) of the murine B7-H4 genomic DNA was PCR amplified from a129SvJ bacterial artificial chromosome (BAC) library (Invitrogen,Carlsbad, Calif.) and was cloned into the 5′-arm position of thepKOscrambler vector NTKV-1907 (Stratagene, La Jolla, Calif.). A 5.57 kbDNA fragment downstream of the IgC domain (exon 4) of B7-H4 genomic DNAwas PCR amplified from the same library and was cloned into the 3′-armposition of the same vector to generate a targeting plasmid, resultingin removing IgV and IgC domains from the B7-H4 gene (FIG. 1A). Thetargeting fragment containing the 5′-arm and the 3′-arm sequences of theB7-H4 gene, a positive selection marker NEO, and a negative selectionmarker TK was transfected into 129SvIE embryonic stem (ES) cells. EScell transfectants underwent neomycin drug selection. The targetedclones were identified by Southern blot analysis using a 3′ externalprobe. Chimeric mice were produced by injection of targeted ES cellsinto blastocysts of 136 individuals. Heterozygous B7-H4 (+I-) mice wereobtained from breeding chimeric mice with B6 mice. PCR analysis wasemployed to distinguish the wildtype and deficient B7-H4 allele. Thesequences of the three PCR primers are: (1) 5t-GTTAGATAGGGTCTCACTGGGTAGC(SEQ ID NO:3), (2) 5′-CCTACAGCCTTCAGTATGCCAGAGA (SEQ ID NO:4), (3)5′-AGACTAGTGAGACGTGCTACTTCCA (SEQ ID NO:5). Homozygous mice wereproduced by back-crossing to B6 for more than ten generations before usefor further analysis. B7-H4 KO/RAG-1 KO mice were obtained bybackcrossing B7-H4 KO and RAG-1 KO mice.

B7-H4KO mice were generated by homologous recombination in 129 ES cellsby deleting the entire Ig V and Ig C regions of the B7-H4 gene tocompletely eliminate their interaction with its potential receptor.Exons encoding both the Ig V and Ig C domains of B7-H4 gene werereplaced with a Neo gene cassette (FIG. 1). Targeted recombination of EScells was confirmed by Southern blot analysis and the data from 4independent ES clones is shown. B7-H4+ allele is predicted to have a12.25 kb Spe1 fragment and B7-H4− allele has an 8.9 kb Spe1 fragment.The clones (2 and 3) with both fragments indicate a recombination.Chimeric male mice were derived from these ES clones by standardprocedures. They were backcrossed to C57BL16 (B6) females andheterozygous mutant mice were established from two independentlytargeted ES clones. Heterozygous or homozygous B7-H4 mutant mice werethen identified by PCR analysis of genomic DNA isolated from tailbiopsies. Southern blot analysis confirmed the replacement of genomicDNA. RT-PCR analysis demonstrated B7-H4 mRNA was not expressed in liversof B7-H4-deficient mice. B7-H4KO mice develop normally and give normallitter numbers. These mice were backcrossed to the B6 background for 10generations before they were used in studies described below.

Example 2 B7-H4KO Mice have Enhanced Granulocyte-Mediated Resistance toListeria Infection

Antibodies, Recombinant Protein and Flow Cytometry Analysis

Primary and secondary antibodies against murine Gr-1 and CD11b, whichare directly conjugated with FITC, PE, or APC, were purchased from BDPharmingen (San Diego, Calif.) or eBiosciences (San Diego, Calif.).Non-conjugated primary antibodies were purified from hybridoma culturesupernatant. B7-H4Ig fusion protein was prepared as described by Sica,G. L. et al., Immunity, 18:849-861 (2003). All cells were stained usingstandard protocols as previously described and were analyzed on aFACSCalibur flow cytometry (id). The data was analyzed with SoftwareCellQuest (BD) or FlowJo (Tree Star, Inc., Ashland, Oreg.). For in vivostudies, mAbs were prepared and purified as previously described (id).Anti-NK1.1 hybridoma (PK136) and anti-IFN-γ hybridoma (R4-6A2) werepurchased from ATCC. Anti-Gr-1 hybridoma (RB6-8C5) was a generous giftfrom Dr. Hans Schreiber in University of Chicago. Control mouse IgG, ratIgG, and hamster IgG were purchased from Sigma (St. Louis, Mo.) andfurther purified as previously described (id). Carrageenan was purchasedfrom Sigma. All cell culture media and antibiotics were purchased fromCellgro (Herndon, Va.). Fetal bovine serum (FBS) was from Hyclone(Logan, Utah).

Listeria Infection and Colony Counting

Listeria monocytogenes strain DP-L4056 was kindly provided by Dr. ThomasW. Dubensky Jr. from Cerus Corp. To prepare Listeria stock, Listeriacells were grown in DIFCO Listeria Enrichment Broth (Becton DickinsonCo., Sparks, Md.) to 0.8-1 at OD600 nm. Culture was harvested bycentrifugation and was washed twice with PBS. Pellets were thenre-suspended in stock solution (PBS with 15-20% glycerol) and aliquotedto 200 μl per microtube for storage at −80° C. The colony-forming units(CFU) of Listeria stock were determined by counting colonies of seriesdilutions of the aliquots growing on BBL CHROMagar Listeria plates(Becton Dickinson Co., Sparks, Md.). Prior to infection, Listeria stockwas thawed and diluted in PBS to appropriate concentration of CFU/ml andapplied to mice or cells as indicated. Mice 6-8 weeks old were infectedby intraperitoneal (i.p.) or intravenous (i.v.) injection of indicatedCFU of Listeria. At indicated time points post-infection, a piece ofmouse liver or spleen was cut, weighed, and ground in PBS. The liversuspension was plated on BBL CHROMagar Listeria plates or on agar platesof Listeria Enrichment Broth. Colonies were counted 2 days post plating,and adjusted to CFUIg of liver or spleen.

Listeria Infection of Granulocytes In Vitro.

Granulocytes were isolated similar to the methods described by Chen, L.Y. et al., Hum. Mol. Genet., 12:2547-2558 (2003). Briefly, mice wereinjected i.p. with 3% thioglycollate broth. Four to five hours postinjection, peritoneal cavities of each mouse were washed with 5 ml PBSand cells were harvested by centrifugation. By this method, more than90% harvested cells are Gr-1⁺CD11b+ granulocyte. 1×10⁶ granulocytes wereincubated with 1×10⁸ CFU of LM for 10 min at 37° C. The cultures wereterminated by adding Penicillin-Streptomycin (Cellgro). Subsequently,cells were harvested by centrifugation, plated in 96-well plates. Theplates were incubated at 37° C. and harvested at indicated time points.Cells were lysed immediately by resuspending in 1 ml of sterile water.Cell lysates or diluted cell lysates were plated on agar plates ofListeria Enrichment Broth for colony counting.

Respiratory Burst and Phagocytosis of Granulocytes.

Granulocyte phagocytic activity and oxidative burst activity weremeasured as described by Radsak, M. P., et al., J. Immunol.,172:4956-4963 (2004); Radsak, M. P. et al., Blood, 101:2810-281 5(2003). Briefly, 1×10⁶ granulocytes were incubated with 5×10⁷ ofred-fluorescent micro-beads (FLUORESBRITE® Polychromatic Red 1.0 MicronMicrospheres, Polysciences, Inc. Warrington, Pa.) and 25 μM of DCFH-DA(2′,7′-dihydrochlorofluoresein diacetate, Sigma-Aldrich) for 30-60 minat 37° C. Cells were washed twice with FACS buffer (1% FBS in PBS) andfixed in 1% paraformaldehyde in PBS. Analysis was performed by flowcytometry.

Pathology

The method for tissue processing and staining was described by Dong, H.et al, Nature Med. 8:793-800 (2002). Briefly, spleen specimens of 6-8week old mice were embedded in OCT compound (Sakura Finetek USA,Torrance, Calif.) and frozen at −80° C. Frozen tissues were sliced,mounted and stained with 5 μg/ml Gr-1-biotin antibody. ABC peroxidase(Vector laboratories, Inc., Burlingame, Calif.) and DAB peroxidasesubstrate (Sigma-Aldrich, St. Louis, Mo.) were then applied to slidesaccording to the company protocols. Finally, hematoxylin solution wasused to stain Gr-1 negative cells.

Results

B7-H4KO mice display normal numbers and ratios of T, B, NK, NKT cells,and macrophages. There are no obvious alterations in T cell responses,judged by in vitro proliferation of purified T cells by CD3cross-linking, allogeneic antigen stimulation, or cytolytic T cellresponse to alloantigens. These results indicate that polyclonal T cellresponses to antigens are not impaired in B7-H4KO mice. Consistent withthese in vitro findings, it was also found that B7-H4KO mice have normalresponses to Con-A induced hepatitis (Dong, H. et al., Immunity,20327-336 (2004)), hapten-induced hypersensitivity (Tsushima, F. et al.Eur. J. Immunol., 33:2773-2782 (2003)), and OVA-induced airwayinflammation (Kamata, T. et al, J. Clin. Invest., 111:109-119 (2003)).B7-H4-deficient mice were also found to be comparable to wild-type micein OT-1 and OT-II cell expansion to OVA proteins (Sica, G. L. et al.,Immunity, 18849-861 (2003)), CD4-Vβ138.118.2 T cell expansion tosuperantigens (Tamada, K. et al., J Immunol., 168:4832-4835 (2002)), andCTL activities to allogeneic antigens in vivo (Tamada, K. et al, NatureMed., 6:283-289 (2000)). Normal B cell responses were also observedafter immunization by TNP-KLH (Tamura, H. et al., Blood 97:1809-1 816(2001)). B7-H4KO mice do not develop spontaneous autoimmune diseases upto 1.5 years in SPF condition.

While the data indicates that B7-H4 plays a minimal role inantigen-driven T and B cell responses in assays, these responses wereconducted in the absence of active infection, which usually requires amuch more sophisticated coordination between innate and adaptiveimmunity. To test this possibility, the effect of B7-H4 ablation wasevaluated in mice infected with Listeria monocytogenes (LM) to examinewhether B7-H4 contributes to immunity against infection. Mice werechallenged with an intra-peritoneal dose (i.p.) (2×10⁶ CFU) of LMsufficient to induce lethality. The survival of these mice was thensubsequently evaluated. B7-H4KO mice were significantly more resistantto LM infection: B7-H4KO mice survived much longer than their wild-type(WT) littermates and up to 40% of mice cleared bacteria and livedindefinitely, while all littermates died around day 9 (FIG. 2 a). Thiseffect is correlated with decreased Listeria numbers in the spleens(FIG. 2 b) and liver in B7-H4KO mice. Interestingly, the majority ofmice were dead within 3-4 days, time points at which adaptive immunityis usually not yet developed. The results thus suggest a role of B7-H4in altering the context of the innate immune response.

To address mechanisms of this resistance, the cell compositions of bothinnate and adaptive immunity were examined. The mice were infected withListeria and T, B, NK, macrophages and granulocytes in peripheral bloodand in lymphoid organs were examined by specific mAb. Although therewere no significant differences in NK, macrophages, T cells, and B cellswithin the first 3 days after LM infection, significantly moregranulocytes in spleens were found from LM-infected B7-H4KO mice thanidentically infected WT littermates at day 3 upon infection (FIG. 2 c).Similar results were also obtained in granulocytes isolated from liversand in peripheral blood after infection. In uninfected B7-H4KO mice,however, granulocyte numbers were within normal range of WT controls.The results indicate that the role of B7-H4 is to inhibit granulocyteresponses during LM infection.

To determine if granulocytes are required for the resistance of LMinfection in B7-H4KO mice, granulocytes were depleted by inoculation ofGr-1 mAb. Injection of Gr-I mAb led to rapid decline of granulocytes toundetectable levels at day 2 in spleens. Depletion of Gr-I andgranulocytes led to a significant increase of LM load in livers fromB7-KO mice, in comparison with those treated with either PBS orisotype-matched control mAb (FIG. 2 d). Depletion of NK cells by NKI.ImAb did not affect colony formation of LM in liver, while depletion ofmacrophages by carrageenan increased LM colonies to a moderate but lesssignificant level as compared to Gr-I cell depletion. The results thusshow that Gr-I and granulocytes play a critical role in the resistanceto LM infection in the absence of B7-H4.

Whether B7-H4-deficient granulocytes have modified functionalities weredetermined by co-culture of purified granulocytes and LM.B7-H4-deficient granulocytes display normal uptake and growth inhibitionof LM in culture system (FIG. 3). In addition, respiratory burst andphagocytosis by B7-H4KO granulocytes are also normal, indicating B7-H4KOgranulocytes are functionally indifferent from WT granulocytes.Therefore, increased resistance to LM infection in B7-H4KO mice islikely caused by an increased number, not increased functional capacityof granulocytes.

Example 3 Granulocyte-Mediated Innate Resistance in B7-H4Ko Mice isIndependent of Adaptive Immunity

Activated and memory T cells are important components in the immunityagainst LM (Nathan, C. Nature Rev. Immunol., 6:173-1 82 (2006)). Whilethe data supports that resistance of B7-H4KO mice to LM infectionrequires granulocytes, it is unknown whether adaptive immunity alsocontributes to this resistance. Because increased granulocyte numberspost-LM infection was a major phenotype found in B7-H4KO mice, theresponses of B7-H4KO mice to LM infection were explored in the absenceof adaptive immunity. B7-H4KO mice were backcrossed to the RAG-I KObackground to eliminate T and B cells.

Results

Unlike RAG-1 KO (RKO) mice, which possess small spleens, B7-H4/RAG-1double KO (DKO) mice display enlarged spleens. The spleen sizes of DKOmice are similar to those of WT and B7-H4KO mice in B6 background.Further analysis of cell components in spleen, peripheral blood, liver,and bone marrow revealed that Grl+CD11b+granulocytes increaseddramatically.

RKO and DKO mice were then challenged by administration of a lethal doseof LM to examine their innate resistance. Infection of RKO mice by LMled to exponential growth of LM in liver and 100% mortality by day 4(FIG. 4). In sharp contrast, DKO mice have significantly less bacterialload in the liver at day 2 and the majority of the mice were able tosurvive more than 10 days LM challenge (FIG. 4). Similar exponentialgrowth of LM in other organs including spleens were observed, indicatinga dissemination of LM infection. In contrast to long-term survival of asignificant fraction of infected B6 background B7-H4KO mice (FIG. 2 a),all DKO mice eventually died of infection at day 15, supporting animportant role of adaptive immunity (FIG. 4). Combined with rapidclearance of LM from liver and other organs in DKO mice as early as day2, the results indicate that lack of B7-H4 confers enhanced innateimmunity against LM infection, which is largely mediated throughincreased granulocytes.

Example 4 B7-H4 Directly Inhibits Proliferation of Granulocytes

Bone Marrow Cell Culture and Granulocyte Growth and Inhibition Assay

Bone marrow cells were aspirated and prepared as described by Wilcox, R.A. et al., Blood, 103:177-1 84 (2004). For B7-H4-mediated growthinhibition, B7-H4Ig or control murine Ig were coated in 96-well platesovernight. After extensive washing, BM cells were plated 2×10⁶/well in24-well plates with or without recombinant murine G-CSF (Pepro TechInc., Rocky Hill, N.J.) at indicated concentrations. Cells wereharvested at indicated time points and cell numbers were counted withBeckman Coulter Counter (Beckman, Fullerton, Calif.). To examine cellgrowth, 2×10⁵/well of BM cells were plated in 96-well plates with G-CSF.After being pulsed with ³HTdR, cells were harvested with FilterMate®cell harvester (Perkin Elmer, Shelton, Conn.) 16 hours post ³HTdR pulse.The incorporated ³HTdR was detected by Trilux® Liquid Scintillation andLuminescence Counter (Wallac, Turku, Finland). For cell division assay,BM cells were first labeled with 2 μM of carboxfluorescein diacetatesuccinimidyl ester (CFSE, Invitrogen, Carlsbad, Calif.) and then wereadded to the cultured in 96- or 24-well plates. Cells were harvested atindicated time points, stained with mAb Gr-1 and CD11b and subjected toflow cytometry analysis for CFSE content (2) at different time points.

Results

Increased granulocytes in B7-H4KO mice suggest that B7-H4 play a role indelivering an inhibitory growth signal to granulocytes. Granulocytesfrom B7-H4 KO mice were examined to determine whether they have bettergrowth potential than WT granulocytes. To do so, bone marrow (BM) cells,which contain large numbers of granulocyte precursors, were prepared andcultured from WT or B7-H4 KO mice in the presence or absence of G-CSFfor 3 days to facilitate differentiation of granulocyte/neutrophil. Theproliferation of BM cells was subsequently determined by ³HTdRincorporation. FIG. 5A shows that while BM cells respond to G-CSF byproliferating in a dose-dependent fashion, proliferation of BM cellsfrom B7-H4KO mice was significantly higher than those from WT mice. Flowcytometry analysis of BM cells which respond to G-CSF in the end ofculture, shows that more than 95% of survived cells are CD 11b+Gr-1+granulocytes. While this data is consistent with an inhibitory effect ofB7-H4 in granulocytes, other cellular components in BM cells may alsocontribute to proliferation. To precisely exclude this possibility, BMcells were labeled with CFSE and after stimulation with G-CSF for 3days, the cells were stained with anti-Gr-1+/CD11b+mAbs to monitorgranulocytes for cell division. FIG. 5 b shows that 70%Gr-1+CD11b+granulocytes from B7-H4KO mice (B6) divide at least oncewhereas only 56% granulocytes from WT B6 mice had diluted CSFE. Similar,but more significant differences were found in mice with the RAG-1 KObackground: 86% granulocytes from DKO mice entered division whereas only64.8% granulocytes from RKO mice had diluted CSFE. The results thusindicate that lack of B7-H4 on BM cells increase proliferation ofBM-derived granulocytes.

Considering that the lack of B7-H4 could result in increasedproliferation of BM-derived granulocytes, whether B7-H4 could directlyinhibit their proliferation was determined. To test this, WT BM-derivedgranulocytes were cultured in the presence of recombinant B7-H4Ig fusionprotein and examined proliferation of granulocytes. Proliferation of WTBM cells was significantly inhibited by B7-H4Ig, a fusion protein ofB7-H4 extracellular portion and immunoglobulin Fc. The inhibition wasevident at day 3 of the culture and became more significant at day 4 and5 (FIG. 6 a). Addition of 0.1 ng/ml of G-CSF in the culture, albeitmoderately increasing proliferation of BM cells, did not significantlyovercome B7-H4Ig mediated suppression (FIG. 6 b). Increasing G-CSF to 1ng/ml in the culture, however, could recover B7-H4Ig-mediated growthinhibition of BM cells in large degree (FIG. 6 c). Similar inhibitionwas also observed in B7-H4 deficient granulocytes. Combined together,the results provide further evidence that B7-H4 is inhibitory for theproliferation of granulocytes, which could be reversed by G-CSF.

It has been discovered that B7-H4 can negatively regulate innateimmunity against Listeria infection. It is believed that the effect ofB7-H4 is mediated through growth suppression of granulocytes. In thecontext of broad expression pattern of B7-H4 in peripheral tissue, thedata supports B7-H4 as an important regulatory molecule in the controlof innate immunity in peripheral tissues, in addition to the previouslydescribed role of B7-H4 in the inhibition of T cell responses.

In B7-H4KO mice, the majority of the extracellular portion of B7-H4protein is deleted to assure complete elimination of interaction betweenendogenous B7-H4 and its putative receptor. Ablation of this gene,however, does not have a profound effect on T cell responses topolyclonal and allogeneic antigen stimulation in vitro. Similarobservations have been made in a recent study reported by Suh, W. K. etal. Mol. Cell. Biol., 26:6403-641 1 (2006). While these findingsindicate that B7-H4 does not substantially influence the inhibition ofstrong polyclonal T cell responses to CD3 cross-linking or allogeneicantigens, it is possible that B7-H4 affects more selective steps duringcascade of T cell responses. For example, a recent study shows thatalthough B7-H4KO mice responded normally to several types of airwayinflammatory responses as well as LCMV and influenza infection, the micehave slightly enhanced T-cell immune responses to Leishmania majorinfection. Responses of granulocytes in this knock-out system, however,were not examined. The experiments indicate that a dominant role ofB7-H4 in Listeria infection is to suppress granulocyte-mediated innateimmunity and this effect could also be observed in RAG-1 KO mice in theabsence of adaptive immune system. Therefore, in addition to inhibitionof T cell immunity as reported previously, B7-H4 may play a criticalrole in negative regulation of innate immunity against bacterialinfection.

Although there is slightly increased granulocytes in the spleens ofB61B7-H4KO mice, dramatic increase of granulocytes occur upon LMinfection (FIG. 2). This increase, however, is not simply due toincreased recruitment by LM-induced inflammation. B7-H4 KO mice in B6background have a small increase of granulocytes in blood, bone marrowand spleen without infection. A more dramatic elevation of granulocytesis observed in RAG-1 KO background. In addition, bone marrow cells fromB7-H4KO mice produce more granulocytes in the presence of G-CSFstimulation. Finally, inclusion of B7-H4 protein in culturesignificantly inhibits growth of bone marrow-derived granulocytes. Therole of B7-H4 in the inhibition of granulocytes could be reversed, atleast partially, by addition of higher concentrations of G-CSF inculture. G-CSF is a critical factor for growth and homeostasis ofgranulocyte in vivo. The result suggests that B7-H4 may serve as anegative regulator to antagonize the role of G-CSF in vivo. Combinedtogether, the results support that B7-H4 provides an inhibitory signalfor responsiveness of granulocytes to G-CSF, a foremost growth factorfor granulocytes, and thus may regulate homeostasis of granulocytes.

It has been shown that B7-H4, upon binding to its putative receptor,inhibits cell cycle progression on T cells (Sica, G. L. et al., Immunity18:849-861 (2003); Kryczek, I. et al. J Eicp Med, 203:871-881 (2006)).In the cell culture system, dilution of CFSE and incorporation of ³HTdRare clearly inhibited (FIG. 6 a). Bone marrow cells were observed toundergo proliferation (FIG. 6 a) and cell division (FIG. 5 g) in theabsence of exogenously supplied G-CSF, a key growth factor forgranulocytes. It is possible that endogenous G-CSF is produced by bonemarrow cells and maintains basal level of proliferation in vitro. Thissuppression could be largely reversed by adding G-CSF (FIG. 6 c). Duringthe culture, significant increases of cell apoptosis was not observedfor up to 5 days. Therefore, growth inhibition may be a dominantmechanism in granulocytes by B7-H4 ligation. B7-H4 mRNA is widelyexpressed by various cells while its cell surface expression could belargely contained in cytoplasm as observed in ovarian cancer andinfiltrating macrophages (Kryczek, I. et al., J Eicp Med, 203:871-881(2006)). Surface expression of B7-H4 could be regulated by cytokineswithin the bone marrow microenvironment to inhibit granulocyte growth.

Granulocytes, including neutrophils, are one of the earliest cells toarrive at the site of an infection and are the first line of individualdefense against infection through their capacity to phagocytose (Nathan,C. Nature Rev. Immunol., 6:173-1 82 (2006)). The findings showing anincreased resistance to Listeria infection in B7-H4KO mice implicates anew approach to enhance innate immunity against infection by Listeriaand possibly other pathogens. It is also interesting that B7-H4 KO micein the RAG-1 background have a more profound increase in the number ofgranulocytes and are more resistant to early phase LM infection incomparison with B7-H4 KO mice in B6 background. These data implicate apossible suppressive role of adaptive immunity components including Tand B cells in granulocyte homeostasis and response to Listeriainfection. Therefore, the method to selective blockade of B7-H4expression such as neutralizing mAb or appropriately engineered B7-H4protein with antagonistic activity represents a new approach to increasegranulocytes and enhanced innate immunity against pathogen infection.

Example 5 Soluble B7-H4 in the Sera of Rheumatoid Arthritis PatientsCorrelates with Disease Severity

Patients and Healthy Donors:

Sera samples were obtained from 68 patients with diagnosed RA, 35patients with diagnosed SLE and 24 normal healthy donors under approvalof the Internal Review Board of Mayo Clinic. RA patients were classifiedto 4 groups as follows. 0: no active disease, 1: 1-4 active joints, 2:5-9 active joints, 3: more than 10 active joints with or withoutextraarticular disease.

Detection of Soluble B7-H4, Collagen-Specific Autoantibodies andAnti-dsDNA Autoantibody:

For detection of human sH4, specific mAb hH4.3 (2 μg/ml) and hH4.1 (2μg/ml) against human B7-H4 was used as capture and detection,respectively, in ELISA. To remove Rheumatoid Factor, the sera weretreated with human. IgG agarose (Sigma-Aldrich, St. Louis, Mo.) beforedetection in ELISA. For measurement of collagen-specific autoantibodies,chicken collagen (1 μg/ml) was coated on the plate overnight at 4° C.,and biotin conjugated anti-mouse IgG, IgG1, IgG2a and IgG2b Ab (BD, SanJose, Calif.) as detection antibodies. To measure anti-dsDNAautoantibody levels, dsDNA from salmon testes at 10 μl/ml in PBS wascoated on the plate overnight at 4° C., and HRP conjugated anti-mouseIgG, (BD, San Jose, Calif.).

Western Blot:

The sera was mixed with 2× sample buffer (4% SDS, 0.2% bromophenol blue,20% glycerol in 100 mM Tris buffered saline) and boiled for 5 min. Thesamples were electrophoresed under reducing conditions on a 10% Readygel (Bio-Rad, Richmond, Calif.) and the proteins electroblotted ontoProtran BA85 (Whatman, Florham Park, N.J.). The Immobilon-P sheet wasblocked in 5% nonfat dry milk in PBS for 1 h and incubated with theantibody at 4° C. overnight. After repeated washing (five times 5 min),bound antibody was detected with horseradish peroxidase (HRP)-labeled.

Results

To detect sH4, sera from individual patients with diagnosis ofrheumatoid arthritis based on American Rheumatism Association criteriawere analyzed by enzyme-linked immunosorbent assays (ELISA) using twospecific monoclonal antibodies (mAb) binding to different epitopes onhuman B7-H4. In this assay, 65% (44 out of 68) samples from patientswith RA and 43% (15/35) from patients with SLE were above background andtherefore positive. Evaluation of sH4 in healthy donors (HD) showed only13% (3/24) were positive (FIG. 7 a). sH4 is significantly higher in RAand SLE patients than healthy donors (P<0.05). In addition, the meanconcentration of sH4 in RA (96.1 ng/ml) and SLE (36.9 ng/ml) wassignificantly higher than those of the healthy donors (3.8 ng/ml). Theresults indicate that sH4 is elevated in a significant portion of RA andSLE patients.

Western blot analysis was used to validate the presence of sH4 in serafrom 3 patients with rheumatoid arthritis. Using specific mAb againstB7-H4, the sera from 3 RA patients, who have detectable sH4 in ELISA,showed a single 50-kDa band. This matched the size of predictedextracellular domain of human B7-H4. In contrast, no band was observedin sera from three healthy donors (FIG. 7 b). The data support thepresence of sH4 in the sera of RA patients.

The association of elevated concentration of sH4 with the severity of RAwas investigated. Based on severity of diseases, 68 RA patients wereclassified into 4 groups (0-3) with most severe diseases in group 3 asdescribed in Methods. The mean concentration of sH4 in group 3 (260.7ng/ml) was significantly higher than those of group 0 (22.0 ng/ml) orGroup 1 (18.8 ng/ml). However, there was no significant difference amonggroup 0-2 by Scheffe test (FIG. 7 c). The data thus indicate that RApatients in group 3 have highest level sH4 and suggest that sH4 mightplay a role in the progression of severe RA.

Example 6 Soluble 137414 Exacerbates Collagen-Induced Arthritis in aMouse Model

Mice

Male DBA/1j mice, MRL-lpr/lpr mice and C57BL/6-lpr/lpr (B6-lpr/lpr) wereobtained from the Jackson Laboratory (Bar Harbor, Me.). Age-matchedmice, 4-10 weeks old, were used for all experiments. B7-H4KO mice weregenerated in this laboratory as described above and have beenbackcrossed to B6 background for 10 generation. DBA/1j×B7-H4KO mice weregenerated by backcrossed B7-H4KO mice into DBA/1j backgrounds for 5generations. B6-lpr/lpr×B7-H4KO mice were obtained by backcrossingbetween B6-lpr/lpr and B7-H4KO mice. All mice were maintained in theAnimal Facility at Johns Hopkins Hospital under approval protocol by theInstitutional Animal Care and Use Committee.

Induction of Collage-Induced Arthritis:

CIA was induced in 8-10 weeks old male DBA/1j mice by intradermal tailbase injection of 0.2 mg chicken collagen (Sigma-Aldrich, St. Louis,Mo.) in 0.05 M acetate acid, supplemented with 4.0 mg/ml mycobacteriumtuberculosis (DIFCO, Detroit, Mich.) emulsified in complete Freundadjuvant. Fourteen days after first primary immunization, the mice wereidentically boosted once. Severity of disease was evaluated by visualinspection of the paws. Each paw was scored for the degree ofinflammation on a scale from 0 to 4: 0, no evidence of erythema andswelling; 1, erythema and mild swelling confined to the midfoot(tarsals) or ankle joint; 2, erythema and mild swelling extending fromankle to the midfoot; 3, erythema and mild swelling extending from ankleto metatarsal joints; 4, erythema and severe swelling encompassing theankle, foot, and digits. Scores from all four paws were added to givethe total for each animal.

Murine B7-H4 Constructs

B7-H4Ig construct was prepared as described by Sica, G. L. et al. B7-H4,a molecule of their family, negatively regulates T cell immunity.Immunity 18, 849-61 (2003)). To generate B7-H4V and B7-H4VC plasmids, 2flanking 5′ and 3′ primers were designed with XhoI and EcoRI restrictionsites, respectively (5′ primer; 5′-ccgctcgagccaccatggcttccttggggcag-3′(SEQ ID NO:6), 3′ primer for B7-H4V;5′-cggaattccgctaatttatctctggcatact-3′ (SEQ ID NO:7), 3′ primer forB7-H4VC; 5′-cggaattccgctaagagttcagcaactgcag-3′ (SEQ ID NO:8)).Appropriate regions of cDNA were amplified using primers. PCR productwas digested with XhoI and EcroRI and ligated into XhoI/EcroRI-digestedpcDNA3.1 vectors (Invitrogen, Carlsbad, Calif.).

Collagen-Specific T Cell Proliferation and Cytokine Production.

The spleen was removed on day 14 after the last immunization. CD4+ Tcells were purified by using magnetic beads (Miltenyi Biotec, Auburn,Calif.). Whole splenocytes or purified CD4+ T cells were stimulated withdenatured (60° C., 30 min) chicken type II collagen (CII) in 96 wellflat bottom microtiter plates for 72 hr, and pulsed with [³H] thymidine(1 μCi/well) (Amersham Pharmacia Biotech, Piscataway, N.J.) for the last12 hr. In the culture of purified CD4+ T cells, irradiated (50Gy)splenocytes from the syngeneic mice were added as antigen-presentingcells. Supernatants from the cultures were collected after 48 hr andassayed for mouse IFN-γ (BD, San Jose, Calif.) and IL-17A (eBioscience)using ELISA kit according to the protocols recommended by manufacturer.

Results

To recapitulate and explore possible role of sH4 in the pathogenesis ofRA, a mouse model of collagen-induced arthritis (CIA) was used. CIA is awell-characterized mouse model for human arthritis, in which injectionof collagen into DBA/1j mice induces swelling and progressiveinflammation in large joints and lead to arthritis. To express sH4 invivo, an expression vector, B7-H4VC, was constructed in which thetransmembrane and intracellular domains of mouse B7-H4 cDNA weredeleted, and the truncated gene encoding both IgV and IgC domains wereplaced under the control of CMV immediate early promoter. Anothervector, B7-H4V, containing only IgV domain of B7-H4 was also produced(FIG. 8 a). Upon expression, these truncated proteins/polypeptides areexpected to compete with endogenous B7-H4 on the cell surface to bindits putative receptor. Parental vector is included as the control. By ahydrodynamic expression procedure known in the art, injection of theseplasmids led to expression of sH4 up to 2 μg/ml in the sera, based onspecific capture sandwich ELISA using two anti-murine B7-H4 mAb.

In the CIA model, immunization of DBA/1j mice with collagen led toappearance of arthritic symptom starting around 28 days. Controlvector-treated mice developed arthritis beginning at day 32 and 80% ofmice developed disease on day 60 after first immunization. Injection ofB7-H4VC led to earlier development of disease (17 days) and 100% micedeveloped arthritis around 30 days. Similar results were also seen inthe mice injected with B7-H4V (FIG. 8 b). Furthermore, treatment byeither B7-H4V or B7-H4VC significantly increase severity of arthritis asindicated by increased clinical score (FIG. 8 c), increased swelling offootpad and increased infiltration of inflammatory cells in joints asshown in histopathology analysis.

Assessment of cellular and humoral immune responses revealed thatincreased incidence and severity of arthritis was accompanied withelevated total IgG autoantibodies (FIG. 8 d) as well as other subtypesincluding IgG₁, IgG_(2a) and IgG_(2b) to collagen CII at day 30 afterimmunization and B7-H4VC or B7-H4V treatment (FIG. 12). Stimulation oftotal spleen cells or purified CD4+ T cells from mice, which weretreated with B7-H4VC or B7-144V, by CII also induced much higher levelof proliferation in comparison with mice treated with control vector(FIG. 8 e and FIG. 13). Importantly, IFN-γ and IL-17, two majorcytokines responsible for CIA progression, also increase significantlyin the cultures (FIG. 80. Taken together, the data demonstrate that sH4enhance autoimmune responses against CII and exacerbate autoimmune CIA.

If B7-H4VC and B7-H4V act as a decoy to block the effect of endogenousB7-H4 on the cell surface, a similar exacerbation effect that shouldalso be observed in B7-H4 deficient mice (B7-H4KO). To test this,B7-H4KO phenotype mice were backcrossed to DBA/1 j background for 5generations. B7-H4KO-DBA/1j mice develop normally and do not haveobvious abnormality in gross appearance and development of immunesystem. These mice, however, developed much more severe CIA, showinghigher accidence (FIG. 8 g) and clinical score (FIG. 8 h) than B7-H4+/+control mice, results similar to those from B7-H4VC or B7-H4V-treatedmice. Therefore, the data support that sH4 functions as a decoy moleculeto increase autoimmune responses and exacerbate CIA.

Example 7 Increased Neutrophils are Responsible for Exacerbation of CIAby sH4

Air Pouch Assay for Neutrophils

The air pouch assay was performed as described by Edwards, J. C. et al.,J Pathol, 134:147-56 (1981). Briefly, mice were anesthetized with 2, 2,2-Tribromoethanol (Sigma-Aldrich, St. Louis, Mo.) and subcutaneousdorsal pouches were created by injection of 5 ml of sterile air. After 3day, pouches were re-injected with 3 ml air. On day 6 after the firstinjection, 50 μg LPS in 1 ml PBS was injected into the pouches. Fivehours later, mice were anesthetized and pouches were lavaged with 3 mlPBS to collect infiltrating cells.

Results

B7-H4KO mice are resistant to Listeria infection due to rapid increaseof neutrophils. Further experiments demonstrated that B7-H4 coulddirectly inhibit growth of neutrophil progenitors. Therefore, sH4 mayblock endogenous B7-H4 and thereby exacerbate CIA vianeutrophil-mediated inflammation, a hypothesis which may provide aninterpretation for progressive inflammation of RA. Whether or notexpression of sH4 increases neutrophils in murine peripheral tissues wasexplored. Due to difficulty to directly access neutrophil number in RAlesions in mouse, an air pouch assay in which neutrophils could becollected from subcutaneous air pouches upon induction of inflammationwere used. As shown in FIG. 9 a, mice injected with B7-H4V or B7-H4VChad significantly more neutrophils in each air pouch than that ofcontrol vector. Together with previous studies in B7-H4KO mice, theresults indicate that sH4 induce a rapid increase of neutrophils inperipheral tissues in viva.

Neutrophils were depleted to investigate whether the effect of sH4 inCIA exacerbation could be eliminated. CIA-mice were treated with B7-H4VCor B7-H4V and subsequently treated with anti-Gr-1 antibody every otherday to deplete neutrophils. Enhanced effect of B7-H4V or B7-H4VC in bothCIA incidence (FIG. 9 b) and clinical score (FIG. 9 c) was completelyeliminated by anti-Gr-1 antibody treatment. The results thus supportthat neutrophils are responsible for the effect of sH4 in theprogression of CIA.

Example 8 Soluble B7-H4 Exacerbates SLE-Like Diseases in lpr Mice andEnhances Autoimmune Responses

Urine Protein Excretion

Urinary protein excretion was determined by dipstick analysis (GERMAINE,San Antonio, Tex.). The proteinuria grade was scored from 0 to 4 asfollows: grade 0, normal; grade 1, 30 mg/dl; grade 2, 100 mg/dl; grade3, 300 mg/dl; grade 4, 2000 mg/dl.

Histological Assessments of Arthritis and Nephritis

CIA mice were sacrificed at day 35. The hind paws were removed, fixed inFormalin, decalcified in 10% EDTA, embedded in paraffin, sectioned, andstained with H&E. For histological evaluation of renal disease, micewere sacrificed at 6 months of age. Kidneys were either fixed informalin or snap-frozen in Tissue Tek (Sakura Finetek, Torrance, Calif.)for cryostat sectioning. Formalin-fixed tissue was embedded in paraffin,sectioned, and stained by the periodic acid-Schiff (PAS) method. Frozensections were fixed in acetone and 1% paraformaldehyde, and stained withFITC-conjugated anti-mouse IgG Ab or C3 Ab (ICN/Cappel, Aurora, Ohio).

A significant fraction of SLE patients also have detectable sH4 in sera(FIG. 7 a). It is possible that sH4 may also play a role in theprogression of SLE. To test this, sH4 was investigated to determinewhether it could promote autoimmunity in MRL-lpr/lpr mice, in which themice spontaneously develop progressive SLE-like symptoms largely due tothe effects of autoantibodies and lymphoproliferation. MRL-lpr/lpr micewere treated with the B7-H4VC plasmid and anti-dsDNA autoantibodies insera were evaluated. As shown in FIG. 10 a, upon treatment by theB7-H4VC, concentration of anti-dsDNA autoantibodies in sera elevatedsignificantly higher than the mice treated with control plasmid at 10weeks. Depletion of neutrophils by injection of anti-Gr-1 antibodycompletely eliminated this effect, a result similar to the observationin the CIA model. This initial study suggests that sH4 also plays a rolein promoting autoimmune responses in this SLE model.

To facilitate analysis of the immune responses and the role of sH4 inthe pathogenesis of SLE, B7-H4−/− phenotype mice were backcrossed toB6-lpr/lpr mice, a strain with similar but less aggressive SLE-likesymptoms as the MRL-lpr strain. As expected, anti-dsDNA IgGautoantibodies were developed much earlier and in much higher titers inB6-lpr/lpr×B7-H4KO mice than the control B6-lpr/lpr mice (FIG. 10 b).Importantly, B6-lpr/lpr×B7-H4KO mice rapidly developed severesplenomegaly and lymphoadenopathy with significantly increased weight(FIG. 10 c) compared with control B6-lpr/lpr mice. The spleen and lymphnodes were much larger and cellularity of these organs increasedsignificantly in B6-lpr/lpr×B7-H4KO mice than the controls (FIG. 10 c).The major cell components, which are increased significantly upon sH4treatment in these organs, are neutrophils (Gr-1+ CD11b+) and T cells(CD3+CD8+, CD3+CD4+ and CD3+CD4−CD8−B220+). B6-lpr/lpr×B7-H4KO micedeveloped severe glomerulonephritis with interstitial inflammatory cellsinfiltrates, hypercellular glomerulus and increased mesangial cells. Inaddition, the mice also developed vasculitis with perivascular cellinfiltration, the glomerular deposition of total IgG) and C3 as well asincreased proteinuria (FIG. 10 d) within 30 weeks. In contrast, controlB6-lpr/lpr mice have normal kidneys without any visible pathology up to24 months. Taken together, the results demonstrate that sH4 exacerbatesSLE-like diseases in lpr mice by enhancing antibody and cell-mediatedautoimmune responses and pathology.

Example 9 Inhibition of CIA Progression by B7-H4Ig

While the data show that sH4 in RA and SLE murine models promotesprogression of diseases, these data also support that endogenous B7-H4is a checkpoint molecule in suppressing autoimmune responses. Therefore,a potential approach to suppress these autoimmune diseases is toincrease the expression of B7-H4 in agonist form, in order to engage itsputative receptor. The effect of B7-H4Ig fusion protein in which B7-H4extracellular domain was fused to murine IgG2a Fe portion was describedby Sica, G. L. et al. B7-H4, a molecule of the 137 family, negativelyregulates T cell immunity. Immunity 18, 849-61 (2003); Chapoval, A. I.,Zhu, G. & Chen, L. Immunoglobulin fusion proteins as a tool forevaluation of T-cell costimulatory molecules. Mol Biotechnol 21, 259-64(2002). The Fc portion of B7-H4Ig could bind Fc receptor to facilitateagonist effect in vivo. The effect of B7-H4Ig in the progression of CIAwas then tested. In comparison with control plasmid, B7-H4Ig plasmidtreatment one day before CII challenge significantly decreased arthritisincidence and clinical score, as well as delayed the onset of CIA (FIG.11 a & b). Furthermore, B7-H4Ig plasmid treatment suppressed theproduction of total IgG (FIG. 11 c) and IgG₁, IgG_(2a) and IgG_(2b)autoantibodies to CII (FIG. 12). Proliferation of splenocytes and CD4+ Tcells (FIG. 11 d and FIG. 13) as well as IFN-γ and IL-17 production inresponse to CII were also significantly suppressed upon B7-H4Igtreatment (FIG. 11 e). Collectively, the results demonstrate thatB7-H4Ig could work as an agonist to suppress both humoral and cellularautoimmunity. In addition, this method should also be effective insuppressing pathogenesis of CIA.

Example 10 Expression of B7-H4Ig in MRL-lpr/lpr Mice Increases Survival

MRL-lpr/lpr mice were injected with control mIgG plasmid or B7-H4Igplasmid at 6, 8, 10 and 12 weeks of age. All phenotypes were analyzed at19 weeks of age. Each group contained 5-10 mice and each set ofexperiments were repeated at least twice. FIG. 14 is a line graph ofpercent cumulative survival versus age (weeks) in MRL-lpr/lpr miceinjected with control mIgG plasmid (□) or B7-H4Ig plasmid (▪) at 6, 8,10 and 12 weeks of age. FIG. 14 shows that treatment by B7-H4Ig (murine)vector increases survival of MRL-lpr/lpr mice. All phenotypes wereanalyzed at 19 weeks of age.

FIG. 15 is a line graph of IgG autoantibody titer (A_(450nm)) versus age(weeks) in MRL-lpr/lpr mice injected with control mIgG plasmid (□) orB7-H4Ig plasmid (▪). FIG. 15 shows that treatment by B7-H4Ig (murine)vector inhibits autoantibodies (anti-DNA) in MRL-lpr/lpr mice. FIG. 16is a graph of proteinuria grade in MRL-lpr/lpr mice injected withcontrol mIgG plasmid (□) or B7-H4Ig plasmid (□). FIG. 16 shows thattreatment by B7-H4Ig (murine) vector inhibits kidney damage inMRL-lpr/lpr mice (1).

Statistical analysis. Statistical analysis was performed with theMann-Whitney U test for single comparison and ANOVA followed by theScheffe test for multiple comparisons. In all statistical analyses,significance was accepted at P<0.05.

Those skilled in the art will recognize, or be able to ascertain usingno more than routine experimentation, many equivalents to the specificembodiments described herein. Such equivalents are intended to beencompassed by the following claims.

1. A pharmaceutical composition dosage unit comprising a soluble B7-H4antagonist in an amount effective to reduce or inhibit one or moresymptoms of an inflammatory response in an individual in need thereof,and a pharmaceutically acceptable carrier for administration of theantagonist.
 2. The pharmaceutical composition of claim 1, wherein theB7-H4 antagonist is a fusion protein comprising a first fusion partnerincluding all or a part of a B7-H4 extracellular domain fused (i)directly to a second polypeptide or, (ii) optionally, fused to a linkerpeptide sequence that is fused to the second polypeptide.
 3. Thepharmaceutical composition of claim 2 wherein the first fusion partnercomprises the membrane distal IgV domain and the membrane proximal IgCdomain of B7-H4.
 4. The pharmaceutical composition of claim 1 in a kitcomprising the antagonist in a first unit and the pharmaceuticallyacceptable carrier in a second unit, wherein the units are combined foradministration.
 5. The pharmaceutical composition of claim 1 wherein theinflammatory response is associated with an autoimmune disease ordisorder.
 6. The pharmaceutical composition of claim 1 wherein theinflammatory response is neutrophil-mediated.
 7. The pharmaceuticalcomposition of claim 5 wherein the autoimmune disease or disorder isselected from the group consisting of rheumatoid arthritis, systemiclupus erythematosus, alopecia greata, anklosing spondylitis,antiphospholipid syndrome, autoimmune Addison's disease, autoimmunehemolytic anemia, autoimmune hepatitis, autoimmune inner ear disease,autoimmune lymphoproliferative syndrome (ALPS), autoimmunethrombocytopenic purpura (ATP), Behcet's disease, bullous pemphigoid,cardiomyopathy, celiac sprue-dermatitis, chronic fatigue syndrome immunedeficiency, syndrome (CFIDS), chronic inflammatory demyelinatingpolyneuropathy, cicatricial pemphigoid, cold agglutinin disease, Crestsyndrome, Crohn's disease, Dego's disease, dermatomyositis,dermatomyositis—juvenile, discoid lupus, essential mixedcryoglobulinemia, fibromyalgia—fibromyositis, grave's disease,guillain-barre, hashimoto's thyroiditis, idiopathic pulmonary fibrosis,idiopathic thrombocytopenia purpura (ITP), Iga nephropathy, insulindependent diabetes (Type I), juvenile arthritis, Meniere's disease,mixed connective tissue disease, multiple sclerosis, myasthenia gravis,pemphigus vulgaris, pernicious anemia, polyarteritis nodosa,polychondritis, polyglancular syndromes, polymyalgia rheumatica,polymyositis and dermatomyositis, primary agammaglobulinemia, primarybiliary cirrhosis, psoriasis, Raynaud's phenomenon, Reiter's syndrome,rheumatic fever, sarcoidosis, scleroderma, Sjogren's syndrome, stiff-mansyndrome, Takayasu arteritis, temporal arteritis/giant cell arteritis,ulcerative colitis, uveitis, vasculitis, vitiligo, and Wegener'sgranulomatosis.
 8. A method for treating or inhibiting one or moresymptoms of an inflammatory response in an individual in need thereofcomprising administering to the individual an antagonist of solubleB7-H4 in an amount effective to reduce or inhibit the one or moresymptoms of the inflammatory response in the individual.
 9. The methodof claim 8 wherein the inflammatory response is associated with anautoimmune disease or disorder.
 10. The method of claim 9 wherein theindividual has an autoimmune disease selected from the group consistingof rheumatoid arthritis, systemic lupus erythematosus, alopecia greata,anklosing spondylitis, antiphospholipid syndrome, autoimmune addison'sdisease, autoimmune hemolytic anemia, autoimmune hepatitis, autoimmuneinner ear disease, autoimmune lymphoproliferative syndrome (alps),autoimmune thrombocytopenic purpura (ATP), Behcet's disease, bullouspemphigoid, cardiomyopathy, celiac sprue-dermatitis, chronic fatiguesyndrome immune deficiency, syndrome (CFIDS), chronic inflammatorydemyelinating polyneuropathy, cicatricial pemphigoid, cold agglutinindisease, Crest syndrome, Crohn's disease, Dego's disease,dermatomyositis, dermatomyositis —juvenile, discoid lupus, essentialmixed cryoglobulinemia, fibromyalgia—fibromyositis, grave's disease,guillain-barre, hashimoto's thyroiditis, idiopathic pulmonary fibrosis,idiopathic thrombocytopenia purpura (ITP), Iga nephropathy, insulindependent diabetes (Type I), juvenile arthritis, Meniere's disease,mixed connective tissue disease, multiple sclerosis, myasthenia gravis,pemphigus vulgaris, pernicious anemia, polyarteritis nodosa,polychondritis, polyglancular syndromes, polymyalgia rheumatica,polymyositis and dermatomyositis, primary agammaglobulinemia, primarybiliary cirrhosis, psoriasis, Raynaud's phenomenon, Reiter's syndrome,rheumatic fever, sarcoidosis, scleroderma, Sjogren's syndrome, stiff-mansyndrome, Takayasu arteritis, temporal arteritis/giant cell arteritis,ulcerative colitis, uveitis, vasculitis, vitiligo, and Wegener'sgranulomatosis.
 11. The method of claim 8 wherein the soluble B7-H4antagonist comprises a B7-H4 polypeptide comprising at least 80%sequence identity to B7-H4 extracellular domain and is capable ofsuppressing or inhibiting humoral immunity, cellular immunity, or both.12. The method of claim 11, wherein the soluble B7-H4 antagonistcomprises an immunoglobin or fragment thereof.
 13. The method of claim12, wherein the immunoglobin or fragment thereof comprises animmunoglobin Fe region.
 14. The method of claim 8 comprising expressingin the individual a nucleic acid encoding a B7-H4 polypeptide comprisingat least 80% sequence identity to B7-H4 extracellular domain.
 15. Themethod of claim 14 wherein the B7-H4 polypeptide further comprises animmunoglobin Fc region.
 16. A method for assessing the severity or riskof developing an autoimmune disease or disorder comprising obtaining abiological sample from an individual; determining levels of solubleB7-H4 in the sample, and comparing the levels of soluble B7-H4 in thesample to levels in a normal control or controls with levels known to beindicative of a severity or risk of developing an autoimmune disease ordisorder.
 17. The method of claim 16 wherein the autoimmune disease ordisorder is selected from the group consisting of rheumatoid arthritis,systemic lupus erythematosus, alopecia greata, anklosing spondylitis,antiphospholipid syndrome, autoimmune addison's disease, autoimmunehemolytic anemia, autoimmune hepatitis, autoimmune inner ear disease,autoimmune lymphoproliferative syndrome (alps), autoimmunethrombocytopenic purpura (ATP), Behcet's disease, bullous pemphigoid,cardiomyopathy, celiac sprue-dermatitis, chronic fatigue syndrome immunedeficiency, syndrome (CFIDS), chronic inflammatory demyelinatingpolyneuropathy, cicatricial pemphigoid, cold agglutinin disease, Crestsyndrome, Crohn's disease, Dego's disease, dermatomyositis,dermatomyositis—juvenile, discoid lupus, essential mixedcryoglobulinemia, fibromyalgia—fibromyositis, grave's disease,guillain-barre, hashimoto's thyroiditis, idiopathic pulmonary fibrosis,idiopathic thrombocytopenia purpura (ITP), Iga nephropathy, insulindependent diabetes (Type I), juvenile arthritis, Meniere's disease,mixed connective tissue disease, multiple sclerosis, myasthenia gravis,pemphigus vulgaris, pernicious anemia, polyarteritis nodosa,polychondritis, polyglancular syndromes, polymyalgia rheumatica,polymyositis and dermatomyositis, primary agammaglobulinemia, primarybiliary cirrhosis, psoriasis, Raynaud's phenomenon, Reiter's syndrome,rheumatic fever, sarcoidosis, scleroderma, Sjogren's syndrome, stiff-mansyndrome, Takayasu arteritis, temporal arteritis/giant cell arteritis,ulcerative colitis, uveitis, vasculitis, vitiligo, and Wegener'sgranulomatosis.
 18. A method for treating or inhibiting an inflammatoryresponse comprising a) removing biological fluid from an individual; b)removing soluble B7-H4 from the biological fluid to produce treatedbiological fluid; c) returning the treated biological fluid to theindividual.
 19. The method of claim 18, wherein the biological fluidcomprises whole blood or plasma.
 20. The method of claim 18, whereinremoving soluble B7-H4 occurs by ultrafiltration, apheresis, ordialysis.
 21. The method of claim 18, wherein soluble B7-H4 isselectively removed from the biological fluid using immunosorbenttechniques.